Use of thermography in the long-term evaluation of scrotal surface temperature and its impact on seminal quality in stallions

Scrotal surface thermography is a non-invasive method for assessing testicular thermoregulation in stallions; however, few studies have explored the application of this technique concerning the thermal physiology of equine reproductive systems. This study aimed to evaluate the consistency of testicular thermoregulation in stallions over a year using thermography to measure the scrotal surface temperature (SST). Moreover, we assessed the best region for measuring the surface body temperature compared with the SST. Ten light-breed stallions were used in the experiment. Thermographic images of the scrotal and body surfaces (neck and abdomen) were captured. Fresh, cooled and frozen-thawed semen samples were evaluated to verify the impact of thermoregulation on semen quality. Testicular thermoregulation was maintained throughout the year in stallions amidst changes in the external temperature, as evidenced by the weak correlation between the SST and ambient temperature. A lower correlation was observed between the environmental temperature and body surface temperature (BTS) obtained from the abdomen (BTS-A; R = .4772; p < .0001) than with that obtained from the neck (BTS-N; R = .7259; p < .0001). Moreover, both BTS-A and SST were simultaneously captured in a single image. The consistent quality of the fresh, cooled and frozen semen suggests efficient thermoregulation in stallions throughout the year.

121 Anti-Müllerian hormone cutoff values for the selection of oocyte donors in the Gir (Bos indicus) breed

Anti-Müllerian hormone (AMH) has a well-known association with antral follicle count (AFC) and the number of oocytes recovered by OPU in cattle. However, to be used as a criterion to select candidate donors for ART, AMH reference values must be established for each breed. The aim of this study was to estimate AMH cutoff values for selecting oocyte donors in Gir (Bos indicus) cattle. A blood sample was collected at a random day of oestrous cycle from Gir heifers (n=120) at 23.3±0.5 months of age, and the plasma was stored for further AMH analysis by ELISA, using a commercial kit (AL114, AnshLabs) in a private laboratory (LEAC, Sao Paulo, Brazil). Data from 506 ovum pickup-invitro embryo production (OPU-IVEP) sessions (4.2±0.2 per donor) performed in these heifers from 2017 to 2019, starting 120 days after blood sampling, were then analysed. Donors were ranked in quartiles according to the number of total oocytes recovered, viable oocytes recovered, and embryos produced. Those classified in the first quartile for each endpoint were considered poor responders. The AMH values were then analysed using the receiver operating characteristic (ROC) curve, and cutoff values for each endpoint were estimated based on best values for sensitivity and specificity. A second analysis was performed to check which cutoff value would result in a significant increase in average for each endpoint. The OPU-IVEP data were ranked according to corresponding AMH values (smaller to greater), and the average of the selected group of donors was compared with the original group by ANOVA, using the PROC GLM of SAS (SAS Institute Inc.), after successive exclusion of donors with lower AMH concentrations. Results are shown as mean±s.e.m. On average, heifers presented AMH concentrations of 932.9±48.4pgmL−1 (ranging from 112.7 to 2044.8pgmL−1) and produced 32.3±1.5 total oocytes, 25.9±1.4 viable oocytes, and 5.3±0.4 embryos per OPU-IVEP session. The heifers ranked in the third and last quartiles yielded more total oocytes, viable oocytes, and blastocysts than those ranked in the first quartile (P&lt;0.05). Based on the total number of oocytes recovered (59.2±3.1), heifers of the last quartile had an estimated AFC &gt;60. The area under the ROC curve (AUC) for total oocytes, viable oocytes, and embryos produced were 0.77 (P&lt;0.0001), 0.75 (P&lt;0.0001), and 0.72 (P=0.0003), and the estimated cutoffs for AMH concentration were 761.4, 622.5, and 681.5pgmL−1, respectively. After successive exclusions of donors with lower AMH values, averages were greater (P&lt;0.05) at a cutoff value of 632.4pgmL−1 for total oocytes (36.9±1.6 vs. 32.3±1.5; +15.3%), 672.3pgmL−1 for viable oocytes (30.3±1.4 vs. 25.9±1.4; +19.4%), and 776.8pgmL−1 for embryos produced (6.6±0.3 vs. 5.3±0.4; +23.4%). However, the use of these cutoff values to increase the averages would result in the exclusion of 32.8, 37.9, and 50.0% of the potential donors for each endpoint, respectively. In summary, these results demonstrated that an AMH concentration of approximately 700pgmL−1 can be used to select donors with higher oocyte yield and thus to increase IVEP outcomes in Gir heifers. This research was supported by Fazendas do Basa, Fapemig CVZ APQ 03430-17.

7 A record of 485 viable cumulus–oocyte complexes recovered and 165 viable embryos produced in a single ovum pickup session from a Senepol breed donor

The recovery of an exceptionally high number of cumulus–oocyte complexes (COC) in a single ovum pickup (OPU) session is rare, and thus seldom reported in the literature. In the present report, we describe one of these cases. The present data refers to an OPU session performed by author A. O. Resende in a commercial beef farm, located in the rural area of the city of Barretos, Brazil, on October 15, 2019. Breed heifers (N=12) underwent OPU at a random stage of oestrous cycle without any hormonal treatment. Follicle aspirations were performed following the standard operation procedures (SOP) established by ABS Pecplan OPU team, using a portable ultrasound (DP2200, Mindray do Brasil) equipped with a 7.5-MHz microconvex probe, a vacuum pump (WTA), and 18 gauge disposable Jelco catheter (Smith Medical). Invitro embryo production (IVP) was performed at Invitro Technologies laboratory, ABS Pecplan Uberaba, located 140km from the farm. On this day, 1312 oocytes were recovered from the 12 donors. However, a single heifer produced 485 viable COC, from over 500 total COC recovered. The COC from this donor were distributed in four groups, which underwent IVF with Y-sorted semen from four Senepol sires. The invitro embryo production was performed following the SOP established by invitro Technologies, ABS Pecplan. Embryo production was compared among sires by the chi-squared test. Of the 4 sires used during IVF, sire number 4 resulted in a higher blastocyst rate compared with the others (sire 1=25.4%, sire 2=30.6%, sire 3=33.9%, and sire 4=46.3%; P&lt;0.01).The blastocyst rate differed (P&lt;0.01) among sires: 25.4%a (31/122), 30.6%a (37/121), 33.9%a (41/121), and 46.3%b (56/121) for bulls A, B, C, and D, respectively. From the total of 165 viable embryos produced (34.0%), 120 were transferred fresh and the remaining 45 were vitrified using the SOP established by IVB Technologies, ABS. These results highlight the huge potential variation in antral follicle population and number of COC recovered from donors within the same population, breed, and reproductive status. It also shows the potential of IVP in the generation of offspring from high genetic indices.

83 Response to follicle-stimulating hormone superstimulation in heifers with ovarian activity suppressed by active immunization against gonadotrophin-releasing hormone

In the present study, we evaluated the ovarian response to exogenous FSH stimulation in the absence of endogenous LH, using as experimental model heifers immunized against GnRH. Pubertal, cycling Nelore (Bos indicus) heifers were allocated into three experimental groups: (1) non-immunized, FSH stimulated (B−FSH+, n=5), (2) immunized, FSH stimulated (B+FSH+, n=5), and (3) immunized, nonstimulated (B+FSH−, n=5). Active immunization was obtained by 3 subcutaneous injections of 1.0mL anti-gonadotrophin-releasing hormone vaccine (Bopriva, Zoetis), given at 20-day intervals. Effective immunization was characterised by the absence of growing follicles &gt;4mm or corpora lutea (CL) on the ovaries. Follicular wave emergence was synchronized in groups B+FSH+ and B+FSH− by follicle ablation, and in group B−FSH+ by using of a protocol consisting of an injection of 2mg of oestradiol benzoate and 0.5mg of sodium cloprostenol, and insertion of an intravaginal progesterone (P4) device (1g). Four days later (Day 0), groups B−FSH+ and B+FSH+ received 100mg of NIH-FSH-P1 (Folltropin-V, Vetoquinol), injected twice-a-day in 8 decreasing doses, and group B+FSH− received saline. Transvaginal ultrasonography (7.5MHz) was performed daily from Days 0 to 4 and the number and size of follicles were recorded. P4 devices of group B-FSH+ were removed at Day 3. All heifers underwent ovum pickup (OPU) at Day 4, and the cumulus–oocyte complexes (COC) recovered were graded for quality. Viable COC were used for invitro embryo production. The heifers were re-evaluated at Day 11 (7 days after OPU). The GLIMMIX procedure from SAS (SAS Institute Inc.) with repeated-measure statement was used to analyse the effects of group, day, and interactions; and the Chi-squared method was used to analyse binomial data. The results are shown as mean±s.e.m. A progressive increase in average follicle size was observed in groups B−FSH+ and B+FSH+ (P&lt;0.0001), whereas no follicle growth was observed in group B+FSH− (P&gt;0.05). Follicle growth rate was similar between groups B−FSH+ and B+FSH+, and both were greater than group B+FSH− (1.2±0.2 and 1.1±0.1 vs. 0.0±0.1 mm/d; P&lt;0.0001). However, the smaller follicle size in group B+FSH+ at Day 0 resulted in smaller follicle size at Day 4, compared with group B−FSH+ (2.4±0.1 vs. 3.6±0.2 and 6.9±0.7 vs. 8.2±0.6mm, respectively; P&lt;0.05). There was no (P&gt;0.05) difference in the number of COC recovered among groups. The group B+FSH+ yielded fewer (P&lt;0.01) COC of grades I and II and more (P&lt;0.01) degenerated oocytes than groups B−FSH+ and B+FSH− (41.2% vs. 80.0% and 68.0%, and 34.0% vs. 19.8 and 7.0%, respectively). Nevertheless, blastocyst rates were similar (P&gt;0.05) for B−FSH+, B+FSH+, and B+FSH− (57.1%, 45.9% and 44.2%, respectively). Residual follicles or luteal tissue were observed after OPU only in group B−FSH+, resulting in a significant difference in the size of ovaries between Days 0 and 11, compared with that of groups B+FSH+ and B+FSH− (3.7±1.4 vs. 0.2±0.2 and −0.2±0.2cm2, respectively; P&lt;0.05). In summary, exogenous FSH supported follicle growth but did not improve oocyte quality in heifers immunized against GnRH. This research was funded by CAPES.

Short communication: Does previous superovulation affect fertility in dairy heifers?

The aim of this study was to evaluate the potential negative effects of superovulation on subsequent fertility of dairy heifers. Holstein heifers (n = 1,783), 312 to 387 d of age, and 273 to 307 kg of body weight (BW) from 2 commercial farms were enrolled. These animals were first selected to be donors (446) or nondonors (CON, n = 1,327) according to their genomic values. Nondonor heifers (CON) were artificially inseminated (AI) according to standard procedures of each farm after reaching 320 kg of BW. Donor heifers were superovulated using a fixed FSH dose (180 mg NIH-FSH-P1; Folltropin-V, Vetoquinol Brasil, Mairiporã, SP, Brazil) and embryos were collected following standard procedures. Heifers that produced fewer than 8 viable embryos after first superovulation (SOV1, n = 337) were no longer used as donors, whereas the remaining heifers (SOV2, n = 109) were superovulated a second time within an interval of 48 to 54 d. Donor heifers (SOV1 and SOV2) were AI once they reached 320 kg of BW, at least 15 d after the last embryo collection. Data on age at first AI, at conception, and at parturition, as well as the number of services per conception, were analyzed by ANOVA, using the PROC MIXED procedure of SAS (SAS Institute Inc., Cary, NC) procedure. Binomial variables (pregnancy per AI, overall pregnancy rate, open heifers at 500 d age, and late pregnancy loss) were analyzed using the GLIMMIX procedure of SAS. The heifers selected to undergo superovulation twice (SOV2) yielded more total (12.6 ± 5.3 vs. 6.8 ± 4.6; respectively) and viable embryos (8.5 ± 3.8 vs. 3.9 ± 2.8; respectively) than those superovulated only once (SOV1). Age at first AI, conception, and at parturition was greater in SOV2, but not in SOV1 compared with nondonor controls. In addition, pregnancy per first AI, overall pregnancy rate, services per conception, open heifers at 500 d of age, and occurrence of pregnancy losses after 60 d of gestation were similar among CON, SOV1, and SOV2 heifers. In summary, a single superovulation performed before heifers reach a minimum weight for breeding did not affect age at conception, calving or other indicators of reproductive efficiency. On the other hand, heifers superovulated twice were first inseminated at a later age than their birth cohorts, but had similar reproductive performance.

Early resynchronization of non-pregnant beef cows based in corpus luteum blood flow evaluation 21 days after Timed-AI

The study aimed to verify whether a hormone protocol started at Day 13 (D13) after Timed Artificial Insemination (TAI) influences the conception rate. Nelore cows (primiparous and multiparous) from two commercial beef farms (n = 1,431) were first TAI (D0). Timed AI was performed in lots (TAI Lots) ranging from 187 to 346 cows. On D13, regarding the TAI lot, cows were assigned for either receiving (Resynch group, n = 1,002) or not (Control group, a subset of approximately 30%, n = 429) another hormone protocol for resynchronization. The same hormone protocol was used for the first TAI and for the resynchronization, except for 1 mg instead of 2 mg of estradiol benzoate (EB) at the begging of the protocol. Eight days later (D21), the Resynch group was checked for corpus luteum blood flow by color Doppler ultrasonography, and in those detected as non-pregnant, the protocol was completed and a 2nd TAI was performed at D23. Pregnancy diagnosis was later (D30) performed by B-mode ultrasonography in the control group and confirmed in the presumptive pregnant cows from the 1st TAI of the Resynch group. The remaining cows were checked for pregnancy 30 days after the 2nd TAI (experimental Day 53). The statistical model to explain conception rate considered the effects of Group (Control or Resynch), Farm, Parity (primiparous or multiparous), Sire, Technician (who perform AI), TAI Lot and pertinent interactions (Group*Parity, Group*Farm and Group*TAI Lot). The statistical analyses of the model were performed using the Proc Glimmix (SAS virtual University Edition). The conception rate for the 1st TAI was similar (P > 0.4) between Control (50.3%, 216/429) and Resynch group (52.6%, 527/1002). The positive predictive diagnostic on D21 showed high relation with PD30 (90.7%, 527/581). In Resynch group, non-pregnant cows (n = 421, 1002 minus 581) were re-inseminated. The conception rate of the 2nd TAI (42.8%, 180/421) was affected (P < 0.002) by side effects of the Farm (48.5 vs. 33.1%) and Parity (51.2 vs. 40.3%, for multiparous vs. primiparous, p < 0.001). Nevertheless, after the 2 TAIs of the Resynch group, the cumulative conception rate was 70.5% (707/1002). In conclusion, the early resynchronization of cows with a low (1 mg) EB dose and progesterone device at D13 after TAI can be used as a strategy to reduce conception interval in beef cattle, and thus to increase the number of pregnant cows from artificial insemination after the breeding season.

127 Chemokine receptor 2 (CCR2) is expressed in growing oocytes, and its deficiency affects follicular activation and long-term female fertility in mice

Chemokine receptor 2 (CCR2) has important functions in several biological processes, including activation of PI3K/Akt/mTOR signalling, a key pathway in follicular activation. However, there is no report about the role of CCR2 in ovarian follicular physiology. The objectives of this study were (1) to immunolocalize CCR2 in mice ovaries and (2) to evaluate the effects of CCR2 deficiency on follicular growth during adult life and aging. A total of 74 C57Bl/6 (wild type, WT) and 68 B6.129S4-Ccr2tm1Ifc/J (CCR2−/− (knockout)) female mice were used. For objective 1, ovaries were collected from WT mice at 1.5 months old (m.o.), fixed in 4% PFA, embedded in paraffin, and used for immunoperoxidase staining with an anti-CCR2 antibody [EPR19698] (ab222496; 1:200) and using anti-rabbit IgG (Ab6721, 1:100) as a secondary antibody. Also, MII oocytes from oviducts of superovulated WT mice were processed with the same primary antibody for immunofluorescence. For objective 2, body and ovarian weight were evaluated. Follicle populations were assessed in WT and CCR2−/− mice at 1.5, 2.5, 6, 10, and 12m.o., by serial sectioning; the total follicle population was counted in every third section in the whole ovary. Additionally, ovarian total RNA isolation was performed from WT and CCR2−/−. Real-time PCR was used to evaluate differential gene expression according to standard protocols, using primers for Bax, Casp3, Bcl2, Fshr, and B-actin (endogenous control). The data were analysed using the GraphPad Prism Software, using t-test, and a P-value of 0.05 was considered as significant. Localization of CCR2 was observed exclusively on the membrane and cytoplasm of growing oocytes in primary, secondary, antral, and atretic follicles, as well as on ovulated MII oocytes membrane and cytoplasm. Body and ovarian weight were similar between WT and CCR2−/− mice. At 1.5m.o., CCR2−/− mice had more primordial follicles and fewer primary and secondary follicles compared with WT (P&lt;0.05), whereas there was no difference in the antral follicle populations. Follicular activation (primordial to primary transition) and atresia rates were decreased in CCR2−/− (P&lt;0.05) at 1.5m.o. A downregulation of pro-apoptotic genes (Bax and Casp3) was observed on CCR2−/− (P&lt;0.05), while anti-apoptotic Bcl2 was upregulated (P&lt;0.05) compared with WT in 1.5-m.o. animals. A larger ovarian follicular reserve at 1.5, 2.5, and 6m.o., but not at 10 or 12m.o., was observed in CCR2−/− mice. At 6 to 12m.o., CCR2−/− ovulated more (P&lt;0.05) MII oocytes than WT. Altogether, these data may suggest that CCR2 plays an important role in the regulation of ovarian follicular reserve mobilization, potentially affecting reproductive lifespan. Financial support was provided by Fapemig and CNPq.

83 Pregnancy losses after transfer of bovine embryos produced by assisted reproductive technologies

The aim of this study was to evaluate risk factors for pregnancy loss in embryo recipients. We evaluated data from 31,792 embryo transfers (ET), including 859 embryos derived in vivo (IVD), 28,814 produced in vitro (IVP), and 2,119 produced by somatic cell nuclear transfer (SCNT), recorded from 2008 to 2012 on a single commercial farm. Embryos were produced by different in vitro embryo production laboratories, but ET was performed by the same team and within the same herd. Recipients were checked for pregnancy (PR) by ultrasonography 23 days after ET and re-examined on Days 60, 90, and 120 of gestation to identify pregnancy losses (PL). Data were analysed for the main effect of embryo production technique upon PL. For IVD and IVP embryos only, additional risk factors were included in the statistical model, including cryopreservation, type of semen (conventional, sex-sorted, reverse sex-sorted), embryo developmental stage, recipient corpus luteum quality score, use of natural oestrus or synchronization protocol, embryo-recipient synchrony, embryo genetics (taurine v. zebu, dairy v. beef), season (summer v. winter), and fetal sex. Data were analysed using the GLIMMIX procedure of the SAS Software (v 9.3, SAS Institute Inc., Cary, NC, USA). Overall PR was 42.1% (13,395 of 31,792) and PL between days 30 and 60, 60 and 90, and &gt;90 were 8.7, 5.3, and 3.5%, respectively (cumulative PL=17.4%). The SCNT embryos had lower PR compared to IVP and IVD embryos (36.6, 42.5, and 44.2%, respectively; P&lt;0.001) as well as a greater PL in all periods (30-60=45.2, 6.4, and 8.2%; 60-90=3.5, 1.4, and 1.8%; and &gt;90=21.4, 6.3, and 7.1%, respectively; P&lt;0.0001). The PR was similar between fresh and frozen embryos, but lower for vitrified ones (42.9, 43.1, and 39.1%, respectively, P&lt;0.05). Slow freezing resulted in a greater total PL compared to fresh embryos (18.0v. 13.9%, respectively; P&lt;0.05). We observed an interaction between embryo genetics and season. The taurine dairy subgroup had the lowest PR during summer (37.7v. &gt;41.7% in all other groups; P&lt;0.01), but within this group PR increased during winter (37.7v. 44.6%, P&lt;0.05). The PL was greater for taurine than zebu during summer (17.8v. 14.0%; P&lt;0.001), but did not differ during winter (P&gt;0.05). The type of semen, embryo developmental stage, corpus luteum quality score, and embryo recipient synchrony affected pregnancy rates (P&lt;0.05) but not pregnancy losses (P&gt;0.05). Interestingly, the use of ovulation synchronization protocols resulted in similar pregnancy rates but greater pregnancy losses compared to natural oestrus (41.8v. 43.2%, P&gt;0.05; and 15.9v. 22.1%, P&lt;0.05, respectively). Pregnancy loss after 60 days was similar between female and male fetuses (5.0v. 4.9%, respectively; P&gt;0.05). In summary, the assisted technology used to produce and freeze embryos was the main cause of variation in pregnancy losses, which were also affected by the interplay of season by genetic background and by the use of synchronization protocols. Conversely, factors known to affect pregnancy rates, such as embryo developmental stage, corpus luteum quality, and embryo-recipient synchrony, had no effect upon pregnancy loss. Research was supported by Mineirembryo, CAPES, and FAPDF.

Differential expression of LHCGR and its isoforms is associated to the variability in superovulation responses of Gir cattle

The aim of this study was to evaluate the pattern of expression of LHCGR isoforms in Gir heifers characterized as good (10.3 ± 1.2 ova/embryos per flush, n = 5) or poor responders (1.1 ± 0.3 ova/embryos per flush, n = 5) to superovulation protocols. In both groups, an adapted ultrasound-guided follicular aspiration system was used to collect granulosa cells from 8 mm follicles formed either during a synchronized, non-stimulated follicular wave (no stimulation control, NS) or on the fourth day of a superovulation protocol (SOV) induced with 200 IU of pFSH. The recovered follicular fluid was centrifuged and granulosa cells were washed with NaCl 0.9% and kept in RNAlater^®. RNA extraction was performed using a commercial RNeasy Micro Kit and eluted samples were quantified and reverse transcribed using the commercial Superscript III kit. cDNA samples were amplified by real-time PCR using a primer to target LH/hCG receptor gene - not selective for LHCGR isoforms (total LHCGR) - and four sets of isoforms selective primers (S1, S10, S10 + 11, and S11). Analyses were performed using the REST software and expression levels are shown as mean ± SEM. Under physiological conditions (NS), poor responders had a higher expression of total LHCGR (4.9 ± 1.7 fold-change, P < 0.01) as well as isoforms S10, S11 and S10 + 11, compared to good responders. In both phenotypes, superovulation down-regulated total LHCGR expression (-0.5 ± 0.2 and -0.9 ± 0.0 for good and poor responders, respectively; P < 0.05). However, in poor responders the exogenous FSH treatment up-regulated the S10 (2.4 ± 2.0; P < 0.05), S10 + 11 (3.8 ± 3.2; P < 0.01), and S1 isoforms (1.8 ± 1.3; P < 0.05), compared to good responders We conclude that down-regulation of total LHCGR, associated to up-regulation of their inactive isoforms, may have compromised follicle development and thus contributed to the low efficiency of superovulation in heifers with a poor responder phenotype.

101 Effects of Active Immunization Against GnRH in Oocyte Donors with Cystic Ovarian Disease

Cows intensively used as oocyte donors for in vitro embryo production (IVEP) are usually kept nonpregnant for prolonged intervals, exposed to successive hormonal treatments, and frequently become overweight. These are all risk factors for the development of endocrine unbalance and, consequently, cystic ovarian disease (COD). The aim of this study was to evaluate the effect of active immunization against gonadotropin-releasing hormone (GnRH) on (1) ovarian follicular population, and (2) development potential of oocytes used for IVEP. Nelore (Bos indicus) cows (n = 14), previously diagnosed with chronic COD (Faria et al. 2017 Anim. Reprod., in press), weighing 620.0 ± 12.8 kg and with body condition score of 4.1 ± 0.2, were assigned to control (n = 6) or treatment (n = 8) group. Cows in the treatment group received 2 SC injections of 1.0 mL of anti-GnRH vaccine (Bopriva, Zoetis, Brazil), 28 days apart (weeks 0 and 4), whereas cows in the control group received placebo on the same schedule. Transrectal ultrasonography was performed weekly from week 0 to evaluate the number and distribution of follicles among size classes, endometrial thickness, and clinical presence of mucometra. Immunization was considered effective (E-IM) when no follicles ≥5.0 mm were observed on the ovaries during a given examination. Cows having E-IM were then used as oocyte donors for IVEP. Cumulus-oocyte complexes (COC) were collected in 5 consecutive ovum pick-up weekly sessions. As a control for IVEP, oocytes from a slaughterhouse were used, with similar procedures performed on the same days and using the same semen batch. The MIXED procedure of SAS (SAS Institute Inc., Cary, NC, USA) with repeated-measures statement was used to evaluate the effects of treatment, time, and interactions on ovarian endpoints; and the GLM procedure was used to analyse embryo production data. Results are shown as mean ± SEM. There were time and time × treatment effects on ovarian parameters. Treated cows had a decrease (P < 0.05) in the average diameter of the largest follicle and in the number of follicles ≥8 mm, and an increase (P < 0.05) in follicular population after week 6. Nonetheless, individual response to treatment was variable: only 50% of the cows (4 of 8) were E-IM at week 8, whereas 25% (2 of 8) still had COD (largest follicle ≥18.0 mm) at this timepoint. Overall, a negative correlation was detected between follicular population and the diameter of the largest follicle (r = –0.60, P < 0.0001) or the number of follicles ≥8 mm (r = –0.47, P < 0.0001). There was no effect (P > 0.05) of treatment on endometrial thickness or mucometra score. Cows with E-IM produced 22.2 ± 3.6 total and 12.9 ± 2.3 viable COC. Cleavage rate did not differ between E-IM and control (slaughterhouse) oocytes (70.8 ± 7.0 v. 75.1 ± 3.0%, respectively; P > 0.05); however, blastocyst rate was greater in the E-IM group compared with controls (39.7 ± 5.5 v. 20.5 ± 4.7%, respectively; P < 0.02). In summary, our results suggest that active immunization against GnRH leads to variable results in the distribution of the follicular population in cows with COD, but it does not negatively affect IVEP efficiency. This research was supported by Zoetis, CNPq, and CAPES.

134 Effects of Gas Tension During Culture upon Development of Bovine Embryos from Beef (Nellore) and Dairy (Girolando) Breeds

Culture of bovine embryos is a critical step during in vitro embryo production (IVEP) and, as such, has been the focus of numerous studies on cattle IVEP. Improvements of culture conditions to mimic the in vivo maternal microenvironment involves studying the optimal gas tension for pre-implantation embryonic development. In the commercial conditions, there is great variability in results, in part because of the difference between breeds and donors. The objective of this study was to evaluate the effects of culture in high or low oxygen tension upon the development of embryos from a crossbred dairy breed (Girolando F1; Gir × Holstein) and a beef Bos indicus breed, Nellore. We collected data from an IVEP commercial operation located in a tropical area of southeastern Brazil (Minas Gerais State) from February to May 2017. The study was designed in a 2 × 2 factorial arrangement of treatments: 2 O2 tensions during culture (5%, low O2 v. 20%, high O2) and 2 breeds (Nellore, beef v. Girolando F1, dairy). Thus, the following 4 groups were studied: Nellore-high O2 (n = 86 donors), Nellore-low O2 (n = 107 donors), Girolando F1-high O2 (n = 114 donors), and Girolando F1-low O2 (n = 110 donors). Outcome variables were the number of cleaved embryos 72 h post-insemination (hpi), cleavage rate relative to the total number cumulus–oocyte complexes (COC) put in culture, number and percentage of blastocysts 192 hpi relative to the structures kept in culture. Variables that were not normally distributed were transformed using the formula log(y + 0.05). Data were analysed using the GLM procedure of SAS (SAS Institute Inc., Cary, NC, USA) for the main effects of gas tension (low v. high O2) and breed (Girolando F1 v. Nelore). Results are shown as mean ± SEM. Gas tension affected the number of cleaved embryos (10.52 ± 0.92 v. 8.33 ± 0.72 for high and low O2, respectively; P < 0.01) and cleavage rates (40.58 ± 2.49 v. 44.41 ± 2.88 for high and low O2; P < 0.01 in Nellore), but did not affect these variables in Girolando F1 donors (13.23 ± 1.33 v. 10.76 ± 0.76 cleaved embryos, for high and low O2; P = 0.63; 58.01 ± 2.00 v. 60.19 ± 1.97 cleavage rate, for high and low O2; P = 0.80). Nonetheless, the number and percentage of blastocysts were not affected by gas tension in either breed. Results for Nellore were 4.99 ± 0.56 v. 3.51 ± 0.38 blastocysts in high and low O2, respectively (P = 0.051) and 41.92 ± 3.91% v. 39.81 ± 3.77% blastocysts, in high and low O2 (P = 0.11). For Girolando F1, numbers of blastocysts were 5.84 ± 0.66 v. 4.24 ± 0.39 in high and low O2 (P = 0.19) and percentage of blastocysts 49.14 ± 2.97% v. 49.11 ± 3.40% in high and low O2 (P = 0.46). These results suggest that oxygen tension during culture affects IVEP differently depending on breed. The initial period of culture, recognised as critical in IVEP, seemed more sensitive to high O2 tension, particularly in Nellore.

149 EFFECT OF RESVERATROL ANALOGUE ON DEVELOPMENT OF IN VITRO-FERTILIZED BOVINE EMBRYOS

Oxidative stress is one of the main effects of in vitro culture. Generation of reactive oxygen species (ROS) by embryos can be enhanced by the sub-optimal in vitro culture conditions and are associated with a delay in embryonic development. However, supplementation of culture medium with antioxidant agents can minimize the effects of ROS (Guérin et al. 2001 Hum. Reprod. Update 7, 175–189). Resveratrol is an example of a potent antioxidant, and modifications in its structure can improve its biological activity. This study evaluated the effect of AR33 (formula with patent pending), an analogue of resveratrol with high antioxidant activity, on embryo development. Bovine cumulus-oocyte complexes recovered from ovaries collected at the slaughterhouse were in vitro matured for 24 h and oocytes were in vitro fertilized for 20 h, both at 38.8°C under 5% CO2 in air and high humidity. Partially denuded presumptive zygotes were randomly distributed in 4 treatments (with 6 replicates): 0 µM (control, n = 347), 0.1 µM (n = 337), 0.5 µM (n = 277), and 2.5 µM (n = 343) of AR33. The base medium was SOFaa supplemented with 2.5% FCS and incubation conditions were 38.8°C under 5% CO2 in air and high humidity. Half of culture medium was renewed (feeding) at Day 3 and 5 post-fertilization. Cleavage was evaluated at Day 3 and blastocyst rates at Day 7 and 8 post-fertilization. Data were analysed by logistic regression considering the significance level of P < 0.05. Values are shown as mean ± SEM. Cleavage rate was higher (P < 0.05) for 2.5 µM (69.0 ± 4.4%) than for 0, 0.1, and 0.5 µM AR33 (62.1 ± 2.0%, 60.7 ± 5.9%, and 56.7 ± 5.8%, respectively). At Day 7, the blastocyst rate was similar (P > 0.05) among 0.1, 0.5, and 2.5 µM (18.1 ± 5.4%, 17.5 ± 2.9%, and 19.4 ± 3.3%, respectively) and all of them were higher (P < 0.05) than 0 µM AR33 (12.4 ± 2.5%). At Day 8, there was again no difference (P > 0.05) among 0.1, 0.5, and 2.5 µM AR33 (21.0 ± 5.0%, 18.4 ± 2.1%, and 24.6 ± 3.3%, respectively) but only 0.1 and 2.5 µM showed higher (P < 0.05) blastocyst rate than 0 µM AR33 (15.2 ± 2.5%). In conclusion, the synthetic analogue of resveratrol tested in this study can improve bovine embryo development in culture medium supplemented with 2.5% FCS under 5% CO2 in air. A concentration of 2.5 µM AR33 can be a choice for further studies. This study was supported by Fapemig, CAPES, and CNPq.

Intrafollicular oestradiol production, expression of the LH receptor (LHR) gene and its isoforms, and early follicular deviation in Bos indicus

The aim of the present study was to characterise the roles of intrafollicular oestradiol production and granulosa cell (GC) expression of the LH receptor (LHR) gene and its isoforms during follicular deviation in Bos indicus. Follicular wave emergence was synchronised in heifers from a Bos taurus dairy (Holstein; n = 10) and a B. indicus dairy breed (Gir; n = 10). Follicles were aspirated individually at sizes corresponding to the periods of predeviation, deviation and postdeviation. Intrafollicular oestradiol (IF-E2) and progesterone (IF-P4) concentrations were determined in the follicular fluid (FF) by radioimmunoassay, and relative expression of P450 aromatase (CYP19A1) and LHR forms was evaluated in GC using real-time quantitative–polymerase chain reaction. Despite differences in the size of the dominant follicle at deviation, changes in CYP19A1 expression and IF-E2 concentrations were similar in follicles of the same diameter in both breeds. A peak in total LHR expression occurred after follicular deviation in association with low expression of LHR isoforms. The results suggest that regulation of LHR function by sequential changes in the expression pattern of LHR isoforms may play a role in the early deviation of the dominant follicle, as observed in B. indicus breeds.

Polymorphisms and alternative splicing of the luteinizing hormone receptor of dairy cattle

The aim of this study was to screen for variability in the luteinizing hormone/choriogonadotropin receptor (LHCGR) and to determine the occurrence of LHCGR mRNA isoforms in two dairy breeds of cattle. Granulosa cells from dominant ovarian follicles were recovered from 16 Gir and 16 Holstein cows, and total RNA was extracted. Complementary DNA was synthesized and PCR was used to generate amplicons for sequencing. Chromatograms were evaluated, and multiple sequences were aligned and analyzed for the presence of polymorphisms, allele frequency, polymorphic information content (PIC), and Hardy-Weinberg equilibrium (HWE). Twenty-one single nucleotide polymorphisms (SNPs) were identified in LH receptor mRNA. Seventeen SNPs were identified in Gir cattle (seven exclusively), and 14 were found in Holstein cattle (four exclusively). Seven of the 21 polymorphisms found did not alter which amino acid was translated. Eight SNPs caused a change to an amino acid in a different chemical group. Classification of SNPs according to PIC values identified 12 as being highly informative in Gir cattle and five in Holstein. Eight SNPs deviated from HWE in Gir compared with 11 in Holstein, and eight in both breeds. Two isoforms were also identified, one in exon 1, which lacks 30 nucleotides beginning at position 118, and the other in exon 10. Taken together, these data show that LHCGR in dairy cattle breeds has a high frequency of polymorphism and exists in multiple isoforms resulting from alternative splicing.

132 BLASTOCYST PRODUCTION FROM BOVINE OVARIAN CORTEX FRAGMENTS XENOGRAFTED UNDER THE BACK SKIN OF MICE

Chemo- or radiotherapy negatively affects the fertility of female patients undergoing oncological treatments. Ovaries are sensitive to such treatments, resulting in an increasing number of premature ovarian failures. Graft techniques are a promising alternative to preserve the fertility of such patients. So far, 35 birthed from human ovarian cortex autografts were reported in the literature; however, in this approach there is a risk of neoplastic reincidence. The aim of the present study was to evaluate the feasibility of ectopic ovarian cortex xenograft (using the bovine model) under the back skin of immunodeficient mice. Female SCID mice (~60 days, n = 38) were anesthetized with ketamine/xilazine and were placed on ventral decubitus. Ovarian cortex fragments from 8 cows (1.5 mm3; n = 152) were grafted through incisions made in the dorsal region (4 grafts per mouse). Ten days after ovarian fragments xenograft, the recipients were killed and the xenografts were harvested. The mice and grafts were weighed before and after the transplant. From the xenografts recovered, 88 were either routinely processed for histology (n = 26), to evaluate the progression of folliculogenesis, or sliced (n = 62) to recover the cumulus‐oocyte complexes, which were morphologically classified and used for in vitro embryo production, using standard procedures (in vitro maturation, fertilization, and embryo culture). The remaining grafts recovered (64) were stored in liquid nitrogen for future studies. Differences between means were compared using Student’s t-test. There was no difference between the body weight of recipient mice before and after xenograft (20.5 ± 0.4 v. 21 ± 0.8 g, respectively; P > 0.05). On the other hand, the grafts increased weight (11.6 ± 3.4 v. 14.8 ± 5.2 mg before and after transplant; P < 0.01). Histological analysis of the slices showed primordial, primary, multilaminar, antral, and atretic follicles, indicating the progression of folliculogenesis and neo-angiogenesis in the grafts. Twenty-four viable cumulus‐oocyte complexes were recovered from ovarian xenografts, from which 2 blastocysts were produced in vitro 8 days later (8.3% blastocyst rate). In summary, this study showed that ovarian xenografts were (i) healthily maintained under the back skin of immunodeficient mice, (ii) responsive to murine gonadotrophins, and (iii) able to produce viable cumulus-oocyte complexes that, (iv) by in vitro fertilization, can originate blastocysts. In general, our findings show the feasibility of the ovary xenograft as an alternative technique to fertility preservation in oncogenic patients, avoiding the risk of neoplastic re-incidence. Study approved by Animal Experimentation Ethics Committee/FUSJ-009/15. Financial support was received from Fapemig and CNPq.

167 EFFECT OF DNA METHYLATION INHIBITOR ON HETEROCHROMATIN IN BOVINE EMBRYOS DERIVED FROM HEAT-SHOCKED OOCYTES

The cell response to stress involves epigenetic modifications in order to regulate the gene expression, which is dependent of chromatin structure and DNA methylation status. On the other hand, changes on DNA methylation can have an effect on chromatin organisation (Espada and Esteller 2010 Semin. Cell. Dev. Biol. 21, 238–246). In this study we evaluated the effect of 5-aza-2′-deoxycytidine (5-aza; Sigma, St. Louis, MO, USA), a DNA methylation inhibitor, on heterochromatin 1 β formation of bovine pre-implantation embryos derived from oocytes that did or did not undergo heat shock during in vitro maturation (IVM). Oocytes were IVM under 38.5°C for 24 h (non-heat-shock: NHS group) or under 41.5°C for 12 h followed by 38.5°C for 12 h (heat-shock: HS group). Oocytes were IVF for 20 h and the denuded presumptive zygotes from NHS or HS groups were cultured with 0 (nontreated controls) or 10 nM of 5-aza for 24 h or 48 h in CR2aa plus 2.5% FCS at 38.5°C with 5% CO2, 5% O2 and 90% N2. Embryos with 4–7 cells at 44 h post-insemination (hpi) and embryos with 8–16 cells at 68 hpi were fixed in 4% paraformaldehyde and stained with anti-mouse HP1β first antibody, then immunofluorescence was evaluated by confocal microscopy (Leica TCS SP5II) and images were processed by ImageJ 1.49 (NIH, Bethesda, MD, USA). Fluorescence of nuclei and of background area (fluorescence/unit area) were measured and then the corrected relative fluorescence per nucleus was calculated. We analysed 129 and 149 nuclei at 44 hpi from 29 and 34 embryos as well as 268 and 182 nuclei at 68 hpi from 37 and 22 embryos of the NHS and HS groups, respectively, obtained from 3 replicates. Data underwent log-transformation and was analysed by ANOVA, and means compared by Student-Newman-Keuls. Embryos with 8–16 cells derived from NHS oocytes and treated with 5-aza for 24 h or for 48 h had nuclei with lower HP1 fluorescence than their respective NHS (nontreated) control (P < 0.01). In contrast, 8–16-cells embryos derived from HS and treated with 5-aza displayed nuclei with the same HP1 fluorescence of their respective HS control (P > 0.05). When embryos derived from HS and NHS (nontreated) control groups were compared, higher HP1 fluorescence was found in those with 4–7 cells of HS group (P < 0.05); however, embryos with 8–16 cells displayed similar HP1 fluorescence between both NHS and HS control groups (P > 0.05). There was no difference on HP1 fluorescence between nuclei of embryos with 4–7 cells treated with 5-aza for 24 h and control (nontreated) in both HS and NHS groups. These data suggest that embryos derived from heat-shocked oocytes can accumulate more heterochromatin at earlier stages than those from non-heat-shocked oocytes and that the effect of DNA methylation inhibition by 5-aza on embryo heterochromatin can vary accordingly to the exposure of the oocyte to heat shock during in vitro maturation. Financial support from CNPq, Fapemig, and CAPES is acknowledged.

Corpus luteum blood flow evaluation on Day 21 to improve the management of embryo recipient herds

The aim of the present study was to use blood flow evaluation of the CL at 14 days after embryo transfer to detect nonpregnant animals and optimize the management of bovine recipients. The estrous cycle was synchronized in 165 recipients, and the day of expected ovulation was considered to be Day 0. Embryo transfer was performed 7 days later, on Day 7. On Day 21, pregnancy was diagnosed on the basis of blood flow evaluation of the CL (DG21-predictive diagnostic). To validate this methodology, visual scores for blood flow were compared to objective data extracted from CL ultrasound images recorded in the Doppler mode. The size was also evaluated using recorded images of the CL in the B mode. Blood samples were also collected for further analysis of the progesterone (P4) concentration. The diagnosis of pregnancy was confirmed at 35 days after estrus (DG35-definitive diagnostic). The DG21 showed that 55.2% (90 of 163) of the animals were presumptively pregnant, and this value was higher (P < 0.04) than that obtained at DG35 (43.6%, 71 of 163). The predictive diagnostic achieved moderate specificity (79.3%) for the detection of pregnancy, but most importantly, high sensitivity (100%) for the detection of nonpregnant recipients. The overall accuracy of the diagnosis was 88.3%. The P4 concentrations were different (P < 0.02) and correlated with each visual score assigned for the CL size. Visual scores for CL blood flow were also efficient (P < 0.0001) to distinguish animals with different levels of P4; however, P4 concentrations were higher for scores 1 and 2 (high and regular blood flow, respectively) than those for score 3 (low blood flow). This technique showed high sensitivity and facilitated the early detection of nonpregnant animals. The DG21 would allow about 79.3% of nonpregnant animals to be resynchronized 9 to 14 days earlier, when compared to conventional management based on pregnancy diagnosis at Days 30 to 35.

Effects of a high-energy diet on oocyte quality and in vitro embryo production in Bos indicus and Bos taurus cows

The effects of different dietary energy levels [100 and 170% for maintenance (M) and high energy (1.7M), respectively] on metabolic, endocrine, and reproductive parameters were evaluated in nonlactating Bos indicus (Gir; n=14) and Bos taurus (Holstein; n=14) cows submitted to ultrasound-guided ovum pick-up followed by in vitro embryo production. The oocyte donor cows were housed in a tiestall system and fed twice daily (0800 and 1600 h). Twenty-one days before the beginning of the experiment, the animals were fed with a maintenance diet for adaptation followed by the experimental diets (M and 1.7M), and each cow underwent 9 ovum pick-up procedures 14 d apart. The recovered oocytes were cultured in vitro for 7 d. We measured glucose and insulin concentrations and performed glucose tolerance tests and the relative quantification of transcripts (PRDX1, HSP70.1, GLUT1, GLUT5, IGF1R, and IGF2R) from the oocytes recovered at the end of the experimental period. No interactions were observed between the effects of genetic groups and dietary energy level on the qualitative (viable oocytes, quality grade, and oocyte quality index) and quantitative (oocytes recovered) oocyte variables. There were no effects of dietary energy level on the qualitative and quantitative oocyte variables. However, Bos indicus cows had greater numbers of recovered structures, viable oocytes, and A and B oocyte grades as well as better oocyte quality index scores and lower DNA fragmentation rates compared with Bos taurus donors. In vitro embryo production (cleavage and blastocyst rates and number of embryos) was similar between diets, but the 1.7M diet reduced in vitro embryo production in Bos indicus cows after 60 d of treatment. Moreover, Bos indicus cows on the 1.7M diet showed lower transcript abundance for the HSP70.1, GLUT1, IGF1R, and IGF2R genes. All cows fed 1.7M diets had greater glucose and insulin concentrations and greater insulin resistance according to the glucose tolerance test. In conclusion, increasing dietary energy did not interfere with oocyte numbers and quality, but the 1.7M diet reduced in vitro embryo production in Bos indicus cows after 60 d of treatment. Finally, Bos indicus cows had greater oocyte quality, greater numbers of viable oocytes and greater in vitro embryo yield than Bos taurus.

347 COULD THE DIFFERENTIAL EXPRESSION OF LUTEINIZING HORMONE RECEPTOR ISOFORMS EXPLAIN THE VARIABILITY IN SUPEROVULATORY RESPONSES IN CATTLE?

Embryo production in vivo is highly variable among donors. The Gir breed (Bos indicus) is well known to show a low embryo production after superovulation (2.5 to 3.5 viable embryos per flush), and a high variance in superovulatory responses, which makes this breed an interesting model to study this trait. The aim of this study was to evaluate the expression pattern of LHR isoforms in Gir heifers previously characterised as good (10.3 ± 1.2 embryos/flush, N = 5) or poor (1.1 ± 0.3 embryos/flush, N = 5) responders to superovulation protocols. In both groups, an adapted ultrasound-guided follicular aspiration system (Arashiro et al. 2012 Reprod. Fertil. Dev. 24, 175) was used to collect granulosa cells (GC) from 8-mm follicles growing in either a synchronized but not stimulated follicular wave (FW) or in the fourth day of superovulation (SOV), induced with 200 UI of FSHp (Pluset, Serono). The recovered follicular fluid was centrifuged and the cells were washed with NaCl 0.9% saline and kept in RNA Later (Ambion, Austin, TX, USA). Total RNA extraction was performed using the commercial RNeasy Micro Kit (Qiagen, Valencia, CA, USA). The RNA samples were quantified and reverse transcribed using the commercial Superscript III kit (Invitrogen, Carlsbad, CA, USA). Complementary DNA samples were amplified through real-time PCR, using a LH receptor primer – not selective for LHR isoforms (total LHR) – and 4 sets of isoform selective primers (S1, S10, S10+11, and S11). All samples were previously tested for theca cell contamination through detection of CYP17A1 gene, and those showing contamination were excluded. The β-actin gene was used as endogenous control. Analyses were performed using the REST software and the expression values are shown as mean ± s.e.m. For comparisons between good and poor responders, the first was set as 1.00. For comparisons between FW and SOV, FW was set as 1.00. In the good responder group, there was no difference (P > 0.05) in total LHR expression among GC samples from FW and SOV. However, the S10+11 isoform was down-regulated (0.4 ± 0.1; P < 0.01) after SOV. In the poor responders group, total LHR expression was down-regulated (0.2 ± 0.1; P < 0.01) after SOV, but there was no difference in the expression of isoforms (P > 0.05). Contrasting the response groups (good and poor), total LHR (15.1 ± 7.6; P < 0.001), and the isoforms S10 (5.7 ± 2.7; P < 0.01), S10+11 (1.9 ± 0.6; P < 0.01), and S11 (5.1 ± 2.5; P < 0.01) were up-regulated in FW of poor responders, but there was no difference (P > 0.05) in any LHR form during SOV. We concluded that 1) LHR expression is different between heifers characterised as good or poor responders to superovulation; 2) superovulation modulates the LHR expression and reduces the original differences observed in unstimulated cycles; 3) diminished expression of total LHR, but not in the isoforms, in poor responders heifers could suggest a reduction in the expression of full-length LHR, with possible consequences to ovulatory capability after superovulation.Financial support was provided by CNPq Project 477701 and Fapemig PPM 0067/11.

241 EFFECT OF PRODUCTION EFFICIENCY IN THE LIKELIHOOD OF PREGNANCY OF IN VITRO-DERIVED BOVINE EMBRYOS

Improving in vitro culture systems to optimize embryo yield has been a major research goal. The relationship between the efficiency of embryo production systems and the pregnancy outcomes, however, remain controversial. The aim of the present study was to evaluate the likelihood of pregnancy of in vitro-produced embryos derived from batches with different relative efficiency indexes. Data of 702 ovum pick-up (OPU) and in vitro embryo production (IVEP) sessions, and of 2456 embryo transfers, recorded from 2008 to 2012, were evaluated. All donors were from the same herd, and were of the same breed (Gir, Bos indicus), as well as the semen used for IVF. The cumulus-oocycte complex (COC) recovery and IVEP were performed by the same team, in a single IVF laboratory, and using standard medium and procedures. Only data from embryos transferred as fresh were used, and records from 97 OPU/IVEP sessions in which no embryo was produced, or embryos were frozen or discharged due to lack of recipients, were discharged. The remaining 605 sessions were stratified in quartiles (I to IV, each one corresponding to 25% of total data) according to COC production of the donors, or stratified in ranges (0–25%, 26–50%, 51–75%, and 76–100%) according to COC quality (percentage of viable COC or of grade I COC) and to embryo production efficiency endpoints (cleavage rate, blastocyst rate). Pregnancy rates were compared among quartiles or ranges by the chi-square method. On average, the Gir donors produced 24.8 ± 0.6 COC per OPU, from which 14.4 ± 0.4 were classified as viable (57.8%), and 3.2 ± 0.1 as grade I (12.9%). On average 6.1 ± 0.2 embryos (morulas and blastocysts) were produced per OPU per donor, and mean pregnancy rate was 30.9%. As expected, donors with greater total COC yield (quartile I) also produced more viable oocytes (25.5 ± 0.7 v. 15.7 ± 0.3, 10.5 ± 0.2 and 5.8 ± 0.2), more COC grade I (4.8 ± 0.4 v. 3.9 ± 0.3, 2.6 ± 0.2 and 1.6 ± 0.1), and more embryos (9.0 ± 0.4 v. 6.9 ± 0.3, 5.0 ± 0.2 and 3.3 ± 0.1) than donors from quartiles II, III, or IV, respectively (P < 0.0001). Nevertheless, there was no difference (P > 0.05) in pregnancy rates for embryos produced from donors ranked in the different quartiles (30.9 v. 29.3, 31.5, and 30.5% for quartiles I to IV, respectively). Similarly, there was no difference (P > 0.05) in the pregnancy rate of embryos derived from OPU sessions in which there was a high or low percentage of viable or grade I COC. In vitro production efficiency (cleavage and blastocyst rates) also had no effect (P > 0.05) on further pregnancy rates. In conclusion, these results suggest that there is no relationship among the average number or quality of the COC recovered by OPU, the efficiency of IVEP, and the likelihood of pregnancy of in vitro-derived embryos.Research was supported by Fazendas do Basa, CNPq, and Fapemig.

292 INHIBITION OF HSP90 AGGRAVATES THE EFFECTS OF HEAT SHOCK ON DEVELOPMENTAL COMPETENCE OF BOVINE OOCYTES

The heat shock protein 90kDa (HSP90) is a chaperone involved in protein homeostasis under normal and stress conditions. Its inhibition by 17-(allylamino)-17-demethoxygeldanamycin (17AAG, Sigma, St. Louis, MO, USA) for 12 or 24 h during in vitro maturation reduces the oocyte's ability to develop after in vitro fertilization (Souza et al. 2014 Reprod. Fert. Dev. 26, 197). This study aimed to evaluate the effect of treatment with 17AAG during the heat shock on oocyte developmental competence. Immature bovine COC were randomly allocated in 4 treatments during IVM: control = no heat shock or 17AAG; HS = heat shock (41.5°C) for the first 12 h of IVM; 17AAG = 2 µM 17AAG for the first 12 h of IVM; and 17AAG + HS = 2 µM 17AAG plus heat shock for the first 12 h of IVM. In vitro maturation was performed in Nunc plate containing 400 µL of TCM199 medium (Invitrogen, Carlsbad, CA, USA) supplemented with porcine FSH (Hertape Calier, Juatuba, Brazil) and 10% oestrus cow serum under 5% CO2 in air, 95% humidity, and 38.5°C for 24 h. Semen was processed by Percoll gradient (Nutricell, Campinas, Brazil) and oocytes were in vitro fertilized for 20 h with 2 × 106 spermatozoa mL–1 under the same IVM atmospheric conditions. Presumptive zygotes were completely denuded in a PBS solution with 0.1% hyaluronidase and then cultured in wells with 500 µL of modified CR2aa medium supplemented with 2.5% fetal calf serum (Nutricell) in an incubator at 38.5°C under 5% CO2, 5% O2, 90% N2, and saturated humidity. Cleavage rate was evaluated 72 h postfertilization and blastocyst rate was evaluated at Day 7 (D7) and 8 (D8). Data from 7 replicates were submitted to analysis of variance and means were compared by Student Newman Keul's test. There was no difference (P > 0.05) on cleavage rate among treatments. Heat shock or treatment with 17AAG, both for 12 h of IVM, decreased (P < 0.05) the blastocyst rate at D7 and D8 when compared to control but no significant difference between HS and 17AAG treatments was found (Table 1). However, the lowest (P < 0.05) blastocyst rate at D7 and D8 was achieved when oocytes were submitted simultaneously to 17AAG and heat shock for 12 h of IVM (17AAG + HS treatment, Table 1). In conclusion, the treatment with 17AAG during IVM worsens the deleterious effect of heat shock on oocyte developmental competence and suggests that HSP90 may also play role on cellular protection during heat shock in bovine oocytes. Table 1.Cleavage and blastocyst (Bl) rates at D7 and D8 for control, 17AAG, Heat Shock (HS), and 17AAG plus HS treatments Financial support comes from CNPq, FAPEMIG, and FAPES.

99 EFFECT OF SEASON AND WEIGHT GAIN ON PREGNANCY RATES OF EMBRYO RECIPIENTS RAISED UNDER PASTURE CONDITIONS

In most Brazilian farms, the management of embryo recipients is done exclusively under grazing systems. Thus, the seasonal variation of grass availability can affect the energy balance and reduce weight gain, and consequently affects the rate of pregnancy. The aim of the present study was to evaluate the effect of the seasonal variation of daily weight gain (DWG) on the pregnancy rate of crossbred heifers (Bos taurus × Bos indicus). The study was performed in the southwest region of Minas Gerais State, Brazil, during one year. Two periods were evaluated: dry (April to September, average precipitation of 470 mm and low grass availability) and rainy (October to March, average precipitation of 1930 mm and high grass availability) seasons. The recipients were kept in a grazing system (Brachiaria brizantha) with water and minerals available ad libitum. Embryos were produced in vitro by the same laboratory, using oocytes and sex-sorted semen from the Gir breed (Bos indicus). A total of 404 fresh embryos (N = 484, 45.4% during dry and 54.5% during rainy season) were transferred by the same technician on Day 7 days of the oestrous cycle – synchronized with prostaglandin – of the recipients, which were weighted at the day of embryo transfer and 23 to 25 days later, at the diagnostic of pregnancy. Animals were retrospectively allocated into 4 groups according to the DWG observed between embryo transfer and pregnancy diagnosis: G1 (N = 132) up to 150 g; G2 (N = 132) between 151 and 250 g; G3 (N = 119) between 251 and 350 g; and G4 (N = 99) greater than 350 g of DWG. The pregnancy rates were compared among DWG groups and between seasons by chi-squared. The logistic regression model was performed using the PROC GENMOD to test the model, including the effects of DWG, season, and the interaction (DWG × season). During the dry season, there was change in frequency distribution of the heifers among DWG groups, with lower frequency (P < 0.05) of heifers in high (G3 and G4) when compared with low (G1 and G2) DWG groups (33.2, 31.4, 21.8, and 13.6% for G1, G2, G3, and G4, respectively). Altogether, pregnancy rate was not different between dry and rainy seasons (42.3 v. 45.8%, respectively; P > 0.05). When compared to G1, pregnancy rate was higher (P < 0.05) for recipients with daily weight gain greater than 250 g day–1 (G3 and G4) (35.6, 40.6, 52.1, and 51.0% for G1, G2, G3, and G4, respectively). Only the effect of the DWG was significant in logistic regression, and the odds rate for each gram of DWG was 0.0039, which means that pregnancy rate improved 1.17 times for recipients with 300 g of DWG. In conclusion, the DWG after embryo transfer, but not the season itself, affect pregnancy rate of in vitro-produced embryo recipients. Biotran, FAPEMIG, and CnPQ are acknowledged.

124 IDENTIFICATION OF LUTEINIZING HORMONE RECEPTOR ISOFORMS DURING FOLLICLE DEVELOPMENT IN CATTLE

The expression of the LH receptor (LHR) is required for the transition from FSH to LH-dependence during the establishment of follicular dominance in cattle. The aim of this study was to identify LHR isoforms expressed before, during, and after follicle deviation, using as models dairy breeds with different dominant follicle sizes at deviation. Mural granulosa cells (GC) were collected using an adapted ultrasound-guided follicular aspiration system (Arashiro et al. 2012 Reprod. Fertil. Dev. 24, 175) from follicles of 6, 8, 10, or 12 mm in diameter of Holstein (Bos taurus), and of 4, 6, 8, or 10 mm of Gir (Bos indicus) heifers. The recovered follicular fluid was centrifuged and the cells were washed with NaCl 0.9% saline and kept in RNA Later (Ambion). Total RNA extraction was performed from GC using a commercial RNeasy Micro Kit (Qiagen), quantified in a spectrophotometer (Nanodrop), and reverse transcribed using the commercial Superscript III kit (Invitrogen). The generated cDNA were PCR amplified using a specific primer for the LHR and designed to detect a region of known occurrence of isoforms. The samples were previously tested for theca cell contamination using a primer to detect the CYP17A1 gene, and those showing contamination were excluded. Results of PCR were analysed by electrophoresis in 5% native acrylamide gel. The frequency of occurrence of the different isoforms was compared by the chi-squared test. In Holstein, the full-length form of the LHR mRNA (459 bp) was detected in all samples. The isoform with total deletion of exon 10 and partial of exon 11 (isoform II; 113 bp) was observed in 4 of 6 follicles of 6 mm and in 4 of 5 follicles of 8 mm. The isoform with total deletion of exon 10 (isoform III; 378 bp) was observed in 4 of 6 follicles of 6 mm, and in all follicles of 8 mm (5/5). The isoform with partial deletion of exon 11 (isoform IV; 194 bp) was observed in 4 of 6 follicles of 6 mm and in 4 of 5 follicles of 8 mm. These 3 alternative isoforms were present in all follicles of 10 mm (4/4) and 12 mm (11/11). There was no difference (P > 0.05) in the frequency of occurrence of the different isoforms. In Gir, the expression of LHR was less regular, no isoform was present in all samples, and no follicle size class showed all isoforms. The full-length LHR mRNA was detected in 2 of 7 follicles of 4 mm, 6 of 9 follicles of 6 mm, 2 of 6 follicles of 8 mm and in all follicles of 10 mm (6/6). The isoform II was observed in 3 of 7 follicles of 4 mm, 3 of 9 follicles of 6 mm, 2 of 6 follicles of 8 mm, and in all (6/6) follicles of 10 mm. The isoform III was observed in 6 of 7 follicles of 4 mm, 7 of 9 follicles of 6 mm, and in all follicles of 8 mm (6/6) and 10 mm (6/6). The isoform IV was observed in 5 of 7 follicles of 4 mm, 6 of 9 follicles of 6 mm, 5 of 6 follicles of 8 mm, and in 5 of 6 follicles of 10 mm. In the Gir breed, the isoform with deletion of exon 10 was the most frequent one (P < 0.01). More than one isoform was observed in most samples. In conclusion, 1) LHR is expressed in GC before follicle deviation, and 2) the expression of LHR isoforms is affected by follicle diameter and breed. The authors acknowledge support from CNPq 477701 and Fapemig PPM 0067/11.

115 FOLLICULAR GROWTH AND BLOOD FLOW OF THE DOMINANT FOLLICLE IN CROSSBRED RECIPIENTS TREATED WITH eCG

This study aimed to explore changes in follicle diameter and blood flow of the dominant follicle (DF), in ovulation and embryo transfer rates, after inclusion of eCG in a protocol for timed embryo transfer. The effect presence or absence of a corpus luteum (CL) at the start of treatment was also included. Crossbred heifers (n = 116, Bos taurus × Bos indicus), with (n = 61) or without (n = 55) CL, were included in the same hormone protocol: Day 0 (D0), insertion of progesterone (P4) device (1.0 g, Sincrogest®, Ouro Fino, São Paulo, Brazil) and 2 mg of oestradiol benzoato (EB, Sincrodiol®, Ouro Fino); D8, removal of P4 device and injection of sodium Cloprostenol (0.250 mg mL–1, Sincrocio®, Ouro Fino). On D8, the animals with and without CL – at the beginning of the protocol – were equally divided into 2 groups (G): G1 – injection of 300 IU (2.0 mL) of eCG (n = 56; Synchro eCG®, Ouro Fino); G2 – 2.0 mL of saline (n = 60). The ovulations were synchronized with 1 mg of EB on D9. From D8 to D11, the diameter of the DF and blood flow in its wall were recorded daily (M5 ultrasound with colour Doppler technology, 7.5-MHz linear array, DPS medical equipment, São Paulo, Brazil). Approximately 100 frames in colour-flow mode, containing entire cross-sections of the DF, were recorded during each examination. The area of the follicular wall with coloured pixels was measured with ImageJ software (Image Processing and Analysis in Java) from the frame with the largest blood flow signal. Before embryo transfer, all heifers were evaluated, and those with good-quality CL received frozen/thawed embryos (ethylene glycol 1.5 mol). Follicle diameter and blood flow area were compared between groups with or without CL before timed embryo transfer protocol and between eCG treatments. The PROC GLM procedure of SAS (version 9.0) and the t-test were used to assess the differences between means. Pregnancy diagnosis was performed on D35. Embryo transfer (ET) rate of the recipients and pregnancy rate were compared between CL or eCG treatments by the chi-squared test. Ovarian status, before hormone protocol, did not change (P > 0.05) the follicular growth of the DF. However, ovulation rate (78.8 v. 65.4%, P < 0.05) and ET rate (78.7 v. 65.4%, P < 0.05) were higher in animals with CL on D0. From D8 to D10, the inclusion of eCG did not affect (P > 0.05) follicular growth and blood flow of the DF. The time effect (P < 0.0001) for follicular blood flow had shown an increase in area of blood flow 24 h after implant removal (7.7 ± 0.7,b 10.2 ± 0.7,a and 12.3 ± 1.0a mm2, for Days 8, 9, and 10, respectively). The eCG did not affect (P > 0.05) the ovulation rate (71.4 and 73.3%, respectively, eCG and no eCG), however, approached an increased (P < 0.06) ET rate (78.8 v. 66.7%). The overall pregnancy rate (51.2%, 43/84) was not affected (P > 0.05) by evaluated variables. In summary, the addition of 300 IU of eCG on D8 of the timed embryo transfer protocol did not change the development of DF but increased the ET rate of the recipients. Biotran, FAPEMIG (project number APQ-1454-12), and CnPQ are acknowledged.

167 INHIBITION OF HEAT SHOCK PROTEIN 90 REDUCES DEVELOPMENTAL COMPETENCE OF BOVINE OOCYTES

The 90-kDa heat shock protein (HSP90) is a chaperone that is important for maintaing protein homeostasis under stress conditions. HSP90 seems also to be required for maturation of Xenopus oocytes (Fisher et al. 2000 EMBO J. 19, 1516) and first cleavage of mouse zygotes (Audouard et al. 2011 PloS One 6, e17109). This study aimed to evaluate the effect of inhibition of HSP90 by 17-(allylamino)-17-demethoxygeldanamycin (17AAG, Sigma St. Louis, MO, USA) during in vitro maturation (IVM) on bovine oocyte developmental competence. Immature cumulus–oocyte complexes (COC) were randomly allocated in 3 treatments during IVM: T0 (control; n = 240), no HSP90 inhibitor; T1: 2 μM HSP90 inhibitor (17AAG; n = 250) for the first 12 h of IVM; and T2: 2 μM HSP90 inhibitor (n = 188) for 24 h of IVM. In vitro maturation was performed in Nunc plates containing 400 μL of TCM-199 medium (Invitrogen, Carlsbad, CA, USA) supplemented with porcine FSH (Hertape Calier, Juatuba, Brazil) and 10% oestrus cow serum under 5% CO2, 95% humidity, and 38.5°C for 24 h. Oocytes were in vitro fertilized for 20 h and incubated under the same IVM conditions. Semen was processed by Percoll gradient (Nutricell, Campinas, Brazil) an IVF performed with 2 × 106 spermatozoa mL–1. Presumptive zygotes were completely denuded in a PBS solution with hyaluronidase and then cultured in wells with 500 μL of modified CR2aa medium supplemented with 2.5% fetal calf serum (Nutricell) in an incubator at 38.5°C under 5% CO2, 5% O2, 90% N2, and saturated humidity. Cleavage rate was evaluated 72 h post-fertilization and blastocyst rates were evaluated at Day 7 and Day 8. Data from 6 repetitions were analysed by generalized linear model procedure of SAS software (version 9.1; SAS Institute Inc., Cary, NC, USA), and means were compared by Student-Newman-Keuls test. Values are shown as mean ± s.e.m. There was a tendency (P = 0.08) for a lower cleavage rate in T2 (52.6 ± 5.8%) than in T0 (control; 74.2 ± 4.1%). Inhibition of HSP90 by 17AAG for 12 h and 24 h of IVM (T1 and T2, respectively) decreased blastocyst rates at Day 7 (20.4 ± 3.0% and 14.3 ± 2.6%, respectively; P < 0.01) and Day 8 (22.6 ± 4.1% and 16.9 ± 2.7%, respectively; P < 0.05) when compared with control (T0 = 31.8 ± 2.5% and 34.1 ± 2.9% for Day 7 and Day 8, respectively). In addition, the inhibition of HSP90 for 24 h decreased (P < 0.05) the proportion of hatched blastocysts at Day 8 (9.5 ± 5.0% for T2, respectively) when compared with control (T0 = 35.8 ± 3.9%), indicating a reduction on embryo quality. In conclusion, inhibition of HSP90 by 17AAG during IVM results in lower developmental competence, suggesting that this protein is also important for bovine oocytes. Further studies are required to investigate if the role of HSP90 on developmental competence of bovine oocyte is affected when under stress conditions. The authors acknowledge CNPq 473484/2011-0, FAPEMIG and FAPES for financial support.

117 INDUCTION OF OVULATION WITH ESTRADIOL BENZOATE AFFECTS THE PROGRESSION OF VASCULARIZATION IN PREOVULATORY FOLLICLES

Ovarian changes in blood supply have been related to follicle growth and ovulation in cattle. The aim of the present study was to characterise the vascularization pattern of the preovulatory follicle in cows induced to ovulate with a timed AI (TAI) protocol using oestradiol benzoate. Follicular wave was synchronized in 18 crossbred cows (Holstein × Gir) with the following protocol: Day 0 (D0), insertion of an intravaginal device of progesterone (1 g, P4) and IM injection of oestradiol benzoate (2 mg, EB); D9, intravaginal P4 device was removed and all the animals received IM injections of cloprostenol (0.53 mg) and eCG (300 IU); D10, animals were randomly allocate into 2 groups, which received 1 mL of saline (control group) or 1 mg of EB (EB group). The vascularization of the largest follicle present in the ovaries was evaluated by colour Doppler ultrasonography immediately before treatment (0 h–0 h) and every 6 h thereafter, up to 84 h or until ovulation was detected. The colour Doppler signals present in the follicular wall were subjectively scored on a 1-to-5 scale (1: no or very few blood flow; 5: intense blood flow detected in most of the follicular wall). The colour Doppler evaluations were performed retrospectively using videos recorded at each examination. The interval from treatment to ovulation was compared by Wilcoxon test. Differences in the vascularization score were compared considering the effects of treatment and time using the PROC MIXED procedure of SAS (SAS Institute Inc., Cary, NC, USA). As expected, in cows treated with EB, ovulations tended to occur earlier (48.0 ± 4.5 h v. 54.0 ± 7.1 h; P = 0.055) and were more synchronous (42–54 h, CV of 9.4% v. 42–66 h, CV of 13.3%) than in the control group. In both groups, follicular vascularization score progressively increased (P < 0.001) until ovulation. However, the vascularization score was lower (P < 0.05) in the EB group than in the control group during the 48-h period before ovulation (overall mean of 2.5 ± 0.7 and 3.0 ± 0.6, respectively); consequently, follicles of cows treated with EB ovulated with a lower vascularization score than did those in the control group (3.6 ± 0.5 v. 4.0 ± 0.5, respectively). Four cows (2 of each group) did not ovulate; follicle vascularization score in these cows remained below 2 during all the evaluation period. In conclusion, although an increase in blood flow is required for ovulation, EB-induced ovulations will occur and are associated with a reduced follicle vascularization. This difference may be related to the smaller interval from treatment to ovulation. Embrapa, CNPq, and Fapemig (CVZ PPM 0067/11) are acknowledged.

16 STRATEGIES OF FOLLICULAR WAVE SYNCHRONIZATION WITH ESTRADIOL BENZOATE IN GYR (BOS TAURUS INDICUS) CATTLE

Physiological and behavioral differences between Bos taurus and Bos indicus can influence the response to a fixed AI protocol. The objective of this study was to examine the reduction of the usual dose of 2 mg of estradiol benzoate (EB) to 1 mg at the beginning of a fixed-time AI protocol, aiming at follicular regression. In a second step, we evaluated the effect of EB on follicle development during follicular pre-deviation and dominance. The experiment was performed at Monte Verde Farm (Uberaba, MG, Brazil). Twenty-two cows (n = 10 heifers and n = 12 nonlactating cows) underwent an estrous synchronization protocol with a progesterone-releasing intravaginal device (P4; Sincrogest®, Ouro Fino Animal Health, São Paulo, Brazil) and received 1 (G1mg, n = 11) or 2 mg (G2mg, n = 11) of EB (Sincrodiol®, Ouro Fino Animal Health), on a random day (designated Day 0). Follicular dynamics was monitored once per day by ultrasonography from Day 0 to 4 with blood sample collections. In a second step, females received 2 mg of EB on Day 3 (GD3, pre-deviation, n = 4) or Day 5 (GD5, dominance, n = 4) of the estrous cycle (Day 0 was the ovulation). Following these treatments, follicular development was monitored daily for 6 days with blood sample collections. The statistical analysis was conducted using the SAS System for Windows 2 (2003; SAS Institute Inc., Cary, NC, USA). The explanatory variables included in the statistical model were the dose of EB, animal category (cows and heifers), and their interaction. The mean test was used to compare intervals from EB treatment to follicular atresia and follicular wave emergence using ANOVA. Progesterone concentrations between groups were compared using the Wilcoxon test. Independently of animal category or stage of the estrous cycle, both EB doses (1 or 2 mg) induced follicular atresia in 2.2 ± 0.9 and 2.1 ± 1.2 days (P > 0.05), respectively. Emergence of a new follicular wave was observed, from Day 0 to 4, in 64% (7/11) of females from G1mg and in 45% (5/11) from G2mg, and the interval between treatment and follicular emergence was 3.4 ± 0.8 and 3.0 ± 1.0 days (P > 0.05), respectively. Plasma progesterone concentrations of the 22 animals increased from 2.1 ± 2.0 ng mL–1 to 7.6 ± 3.0 ng mL–1 by 24 h after the device insertion (P < 0.05), reaching peak concentration (8.0 ± 3.0 ng mL–1) by 48 h after treatment beginning, decreasing to 6.4 ± 2.5 ng mL–1 by 72 h, and remaining constant up to 96 h. Estradiol benzoate injection at follicle pre-deviation (GD3) caused follicular atresia (2.0 ± 1.4 days) and emergence of a new follicular wave in 3.7 ± 0.1 days in all animals (4/4). However, EB injection during follicle dominance (GD5) did not synchronize a new follicular wave and follicles persisted during the time of monitoring. Furthermore, EB applied at dominance hastened luteolysis in 50% (2/4) of the treated animals. In conclusion, a reduced dose of EB (1 mg) at the beginning of the protocol with P4 effectively induces follicular atresia. To synchronize a wave emergence at any stage of the estrous cycle, EB must be associated with an exogenous source of progesterone.

228 IN VITRO EMBRYO PRODUCTION AFTER EXPOSURE OF BOVINE OOCYTES TO DIFFERENT TRANSPORTATION MEDIA AND PERIODS: PRELIMINARY RESULTS

This study was designed to evaluate the effect of different oocyte transportation media and time. Immature oocytes were recovered from slaughterhouse bovine ovaries. Oocytes (n = 492) of quality grades I to III were randomly allotted to one of the following transportation media based on TCM-199, either buffered with HEPES (control) or buffered with NaHCO3 and added with FSH/LH (maturing). Both media were supplemented with pyruvate, penicillin G (10 000 IU), streptomycin (0.05 mg mL–1), and 10% fetal bovine serum (FBS). In control medium, the oocytes were kept for 1 or 8 h at 37°C, and thereafter were transferred to maturing medium until the maturation period (24 h) was completed, under controlled atmosphere (5% CO2) and temperature, in an incubator. The maturing oocytes were distributed in two types of equipment developed for oocyte and embryo transportation, with and without 5% CO2, and kept for 1, 8, or 24 h before maturation or fecundation (IVF) procedures. The oocytes kept for 24 h in the transportation device were placed directly for IVF. All procedures used for in vitro maturation, IVF, and in vitro culture were the same as those adopted for commercial in vitro embryo production at Biotran LTDA (Alfenas, Minas Gerais, Brazil). The cleavage rate was evaluated on Day 3 post-insemination, and the blastocyst production was evaluated on Day 7. The statistical model included the main effects of treatment (control and maturing with or without 5% CO2), time, replicate, and the interaction of media × time. Data (3 replicates) were analysed by ANOVA and differences were identified by Tukey’s test. The time before in vitro maturation at the incubator negatively (P < 0.007) affected cleavage rates (76.4 ± 16.9 v. 58.8 ± 13.2 and 52.2 ± 18.5%, respectively, for 1, 8, and 24 h). However, treatment had no effects (P = 0.3) on cleavage (66.9 ± 15.0, 57.8 ± 19.7, and 67.7 ± 19.8% for the control and maturation with and without 5% CO2, respectively). Similarly, blastocyst production rates differed (P < 0.04) between 1 h (33.4 ± 14.7) and 24 h (19.3 ± 17.0%), whereas blastocyst production at 8 h did not show significant effects (19.3 ± 17.0). Although it was not significant (P > 0.05), only 14.1% of the oocytes kept in medium 2 with a controlled atmosphere for 24 h became embryos. This difference was probably related to the trend in treatment effect (P = 0.06) and the lower rate of embryo production (22.2 ± 13.6%) in this treatment compared with the control (33.8 ± 18.1%) and maturation without 5% CO2 (29.8 ± 17.3%). These results showed that 24 h of transportation is detrimental for the oocyte development potential and that the buffered medium used in this study with 5% CO2 did not efficiently maintain embryo production. Supported by CNPq, CAPES, FAPEMIG, and Biotran LTDA.

172 P450 AROMATASE GENE EXPRESSION, ESTRADIOL PRODUCTION, AND DOMINANT FOLLICLE DEVIATION IN BOS TAURUS AND BOS INDICUS DAIRY HEIFERS

It is well documented that the size of the dominant follicle at deviation is smaller in Bos indicus compared with in Bos taurus breeds. The physiological mechanisms underlying this difference, however, are unknown. The aim of the present study was to evaluate the dynamic of oestradiol production during follicle development close to the expected moment of deviation in Bos taurus and Bos indicus dairy heifers. Intrafollicular concentration of oestradiol (E2) and P450 aromatase gene expression in granulosa cells (GC) were evaluated in Gir (n = 10) and Holstein (n = 10) heifers. Follicular waves were synchronized with an intravaginal progesterone device (1 g, Sincrogest, Ourofino Agropecuária, São Paulo, Brazil) and benzoate oestradiol (2 mg im, Sincrodiol, Ourofino Agropecuária). Ultrasonography evaluations (MyLab30 Vet Gold, Esaote, Genova, Italy, with a 7.5-MHz transducer) were performed every 24 h to detect the emergence of the new follicular waves. The largest follicle of each wave was individually aspirated by ovum pickup before, at the expected diameter, or after deviation in both Gir (4.6 ± 0.2, 6.3 ± 0.2, and 8.5 ± 0.6 mm, respectively) and Holstein heifers (6.0 ± 0.5, 8.6 ± 0.4, and 10.2 ± 0.2 mm, respectively), as previously described (Arashiro et al. 2012 Reprod. Fertil. Dev. 24, 175). Follicular fluid (FF) samples were centrifuged and the supernatant stored at –20°C until E2 and progesterone (P4) determination by RIA. The pellet of GCs was washed twice with PBS, kept in RNAlater, and frozen at –20°C until RNA extraction and reverse transcription. Relative transcript quantification was performed by real-time PCR. The β-actin gene was used as control. Samples of FF with E2:P4 ratio <1 or presenting contamination by theca cells (detected by the expression of 17α-hydroxylase) were not used for statistical analyses. Concentration of E2 in FF was evaluated between breeds and among follicle size classes by ANOVA and differences among means compared by Student t-test or Tukey’s test, respectively. Within breeds, relative gene expression was accessed by pair-wise fixed reallocation randomization test (software REST®). Results are shown as mean ± SEM. In both breeds, concentration of E2 in FF progressively increased with follicular diameter (P < 0.05). Intrafollicular concentration of E2 (ng mL–1) was greater (P < 0.05) in Holstein than in Gir before (58.5 ± 11.7 v. 8.8 ± 2.0), at expected (226.0 ± 49.9 v. 78.9 ± 21.0), and after follicle deviation (579.1 ± 45.0 v. 185.0 ± 34.9). Interestingly, however, follicles with similar diameters (~6 or 8 mm) showed similar (P > 0.05) E2 concentrations between Holstein and Gir. Moreover, in both breeds, the relative expression of P450 aromatase gene in GC first increased (3.9 ± 2.4 and 67.5 ± 52.8 for Holstein and Gir, respectively; P < 0.05) at the same stage of follicular development (8 mm). The present results suggest that the smaller size of follicles at deviation in Bos indicus is not related to an earlier increase in intrafollicular E2 production. CNPq, CAPES, and Fapemig (CVZ APQ 02863/09).

330 TRICHOSTATIN A IMPROVES THE IN VITRO DEVELOPMENT OF CLONED BOVINE EMBRYOS RECONSTRUCTED WITH TRANSGENIC DONOR CELLS

Trichostatin A (TSA), a histone deacetylase inhibitor, has been described as a potential modulator of nuclear reprogramming in bovine zygotes reconstructed by somatic cell nuclear transfer (SCNT), but with controversial results (Lee et al. 2011 J. Reprod. Dev. 57, 34–42; Sangalli et al. 2012 Cell Reprogramming 14, 1–13). The effect of TSA in zygotes reconstructed with transgenic cells cultured for long periods is not known. This study aimed to evaluate the effect of TSA on development of bovine embryos reconstructed with donor cells transfected with a green fluorescent protein (GFP)-reporter transgene. Bovine fibroblasts at second passage were transfected with lentiviral vectors carrying the GFP transgene and cultured at 37.5°C under 5% CO2 in air. Transfected cells were cultured for additional 10 passages to establish a cell lineage expressing the protein. In the 12th passage, the cells were frozen in 10% dimethyl sulfoxide plus FCS (Nutricell, Campinas, Brazil) and frozen–thawed cells expressing GFP were used as nucleus donors. In vitro-matured oocytes were enucleated, fused to GFP positive fibroblasts, and activated with ionomycin. Putative zygotes were randomly distributed into 2 groups: SCNT-CONT (n = 55): zygotes were cultured for 4 h in CR2aa medium plus BSA with 6-DMAP followed by 7 h in CR2aa medium plus 2.5% FCS; SCNT-TSA (n = 49): zygotes were cultured in the same conditions described above, but supplemented with 50 nM TSA (Sigma-Aldrich, St Louis, MO). Then, embryos from all groups were cultured in CR2aa supplemented with 2.5% FCS under 5% CO2, 5% O2, and 90% N2 at 38.5°C. Evaluations of cleavage and blastocyst percentages were performed at 72 and 168 h post-activation, respectively, and 4 replicates were carried out. Expression of GFP in embryos at blastocyst stage was visualised using an epifluorescence microscope. Statistical analysis was performed by ANOVA and data are shown as mean ± SEM. No difference (P > 0.05) on cleavage percentage was found between groups (72.9 ± 11.3% and 66.1 ± 14.4% for SCNT-CONT and SCNT-TSA, respectively). The blastocyst percentage calculated based on putative zygotes tended (P = 0.077) to be higher for SCNT-TSA (16.7 ± 4.0%) than for SCNT-CONT (6.8 ± 2.3%). When the blastocyst percentage was calculated based on cleaved embryos, a higher rate (P < 0.05) was achieved in SCNT-TSA (26.7 ± 3.8%) than in SCNT-CONT (10.3 ± 3.6%) group. Blastocysts of both groups expressed GFP, with no difference among embryos. In a previous study, we reported that TSA had no positive effect on in vitro embryo development or gene expression, despite the reduction on apoptosis index [Camargo et al. 2011 Acta Sci. Vet. 39(Suppl.), S442; Camargo et al. 2012 Reprod. Fert. Dev. 24, 121–122). In the present study, however, the treatment with TSA of zygotes reconstructed with transgenic cells cultured for a long time improved embryo development without impairing GFP expression. This result suggests that TSA may be effective in clones reconstructed with transgenic cells. Supported by Embrapa 01.07.01.002, CBAB/CNPq, CAPES and Fapemig.

125 FOLLICULAR FLUID AND GRANULOSA CELL RECOVERY FROM BOVINE FOLLICLES OF DIFFERENT DIAMETERS USING AN ADAPTED TRANSVAGINAL-GUIDED FOLLICULAR ASPIRATION SYSTEM

Most studies of granulosa cell (GC) function have been performed in vitro, using follicular fluid (FF) and GC recovered from slaughterhouse ovaries. This approach does not consider the reproductive status and follicular developmental stage of the donor, limiting data interpretation and usefulness. The aim of this study was to evaluate the efficiency of an adapted ultrasound-guided transvaginal follicular aspiration (TVFA) procedure to recover FF and mural GC from live cows. A preliminary in vitro trial was performed to calculate fluid losses using a conventional TVFA circuit. A known volume of PBS, expected to be the volume of FF in follicles ranging from 4 to 12 mm in diameter, was aspirated using a 20 G needle connected to a Teflon circuit 80 cm long, with a 1.0-mm internal diameter, connected to a 1.5-mL tube. Losses of the expected volume of FF were 12.7 ± 1.1, 19.9 ± 2.5, 54.4 ± 4.0, 87.6 ± 4.3 and 100%, for follicles of 12, 10, 8, 6 and 4 mm in diameter (0.90, 0.52, 0.27, 0.11 and 0.03 mL, respectively). When an adapted system for small-volume recoveries was used, there was a decrease (P < 0.05) in fluid losses for follicles of 8, 6 and 4 mm. An experiment was performed in vivo, using the adapted system, to evaluate FF and GC recovery from follicles of 4 and 5 (n = 16), 6 (n = 19), 7 (n = 7), 8 (n = 13), 9 (n = 15), 10 (n = 24), 11 (n = 11), 12 (n = 15), 13 (n = 13), 14 (n = 6) and 16 (n = 9) mm in diameter. Follicular wave emergence was synchronized with 2 mg of oestradiol benzoate and an intravaginal progesterone device and follicles that reached the desired diameter were aspirated using an ultrasound machine equipped with a 7.5-MHz probe and disposable 20 G needle. The recovered FF volume was measured and centrifuged at 600 × g for 10 min. The GC pellet was vortexed with 0.1% hyaluronidase (5 min) and washed twice in PBS and the number of cells was determined using a Neubauer chamber. Ribonucleic acid was extracted using an RNAeasy Microkit and quantified in NanoDrop. The efficiency of FF recovery was estimated by the difference between the recovered and expected volumes for each follicle diameter (4/3πr3), which were compared by ANOVA. From all the follicles aspirated, the recovery of FF and GC was not successful in 2 (1.3%). Overall, FF recovery efficiency was 84.7%. The recovered volume ranged from 0.03 to 3.80 mL and increased with follicular diameter (y = 0.011x2 – 0.012x + 0.043; R2 = 0.99). Losses of FF were significant (P < 0.05) for follicles larger than 12 mm. The mean (±s.e.m.) number of mural GC recovered was 716,708 ± 68,536, providing 6.8 ± 0.7 samples of 100 000 cells with 14.8 ± 0.7 ng of RNA μL–1 for each punctured follicle. A high coefficient of variation (57.4%) was observed in cell recovery. There was no difference in the number of cells recovered from follicles of different diameters, but sample contamination with blood was more frequent (75%) in follicles larger than 10 mm. In conclusion, an adapted TVFA system can be used successfully on an individual basis and from follicles of different diameters for in vivo recovery of FF and GC for further endocrine and gene expression analyses. This research was supported by CNPq and Fapemig (CVZ APQ 02863/09).

17 CELL CYCLE SYNCHRONIZATION OF BOVINE FIBROBLASTS BY AZADIRACHTA INDICA EXTRACTS

One requirement for somatic cell nuclear transfer (NT) is the coordination between donor cell cycle and recipient cytoplasm. As an alternative to commercially available substances to synchronize the cell cycle in G0/G1, we tested 2 extracts, aqueous and hexane obtained from the plant Azadirachta indica A. Juss (popularly called Neem). Extracts from this plant have shown antiviral, antibacterial and anticancer activities, widely described in the literature (Kumar et al. 2009 Invest. New Drugs 27, 246–252). The hexane extract was prepared in the Soxhlet apparatus until total collapse and then submitted to rotary evaporation. The aqueous extract was prepared by dynamic maceration and was subsequently lyophilized. Bovine fibroblasts collected from Gyr cows were cultured in DMEM (Sigma) supplemented with 10% fetal cow serum (FCS) and incubated at 37°C, 5% CO2 and 95% humidity. After obtaining 70% of cell confluence, the extract was added to cells at the following concentrations: 0 μg mL–1 (negative control), 50 μg mL–1, 100 μg mL–1, 200 μg mL–1 and 300 μg mL–1, for 12 and 24 h. Simultaneously, a group with serum starvation (positive control; cells cultured in DMEM plus 0.5% FBS for 3 days) was prepared. Three repetitions were performed in triplicate for each concentration and control groups. Cell cycle readings were performed by flow cytometry (Facs Callibur, Becton Dickinson, San Jose, CA, USA) and DNA histograms were analysed by WinMDI software to determine the percentage of cells in G0/G1 phase, S and G2 cell cycle, so that 10 000 cells were analysed in each reading on a flow cytometer. Data were analysed by analysis of variance and means were compared by Student-Newman-Keuls test. The percentages of cells at G0/G1 phase for aqueous extracts were lower (P < 0.05), regardless of the concentration and exposure time, than the 0 μg mL–1 (83.73 ± 1.14%) and serum starvation (86.64 ± 1.44%). In contrast, the percentages of cells synchronized at G0/G1 with 50 μg mL–1 for 12 h (84.23 ± 0.56%), 50 μg mL–1 for 24 h (85.66 ± 0.57%), 100 μg mL–1 for 12 h (87.85 ± 0.51%) and 200 μg mL–1 for 12 h (85.87 ± 0.45%) using hexane extracts were higher (P < 0.05) than with 0 μg mL–1 (81.44 ± 0.29%), but lower (P < 0.05) than the serum starvation (91.33 ± 0.31%). In conclusion, hexane extracts from the plant Azadirachta indica A. Juss can synchronize mammalian cell cycle at G0/G1 despite the low proportion when compared with serum starvation. Studies to evaluate efficiency of cell cycle resuming and viability after somatic cell nuclear transfer are ongoing. Financial support: FAPEMIG, CNPq and Project 01.07.01.002.

20 ALTERED GENE EXPRESSION IN BOVINE SOMATIC CELL NUCLEAR-TRANSFERRED EMBRYOS AFTER TRICHOSTATIN A TREATMENT

Trichostatin A is a histone deacetylase inhibitor that improves histone acetylation and chromatin remodeling of somatic cell nuclear-transferred embryos (Iager et al. 2008 Cloning Stem Cells 10, 371–379; Maalouf et al. 2009 BMC Dev. Biol. 9, 11). We have previously observed that it also improves quality of bovine cloned embryos, which may increase pregnancy rates. This study aimed to evaluate the effect of trichostatin A treatment of zygotes on relative abundance of 9 transcripts in bovine nuclear-transferred blastocysts. In vitro matured oocytes were enucleated, fused to somatic cells and activated with ionomycin (Camargo et al. 2011 Reprod. Fertil. Dev. 23, 122). After activation, putative zygotes were randomly separated into 2 groups: NT-TRICHO, zygotes were cultured for 4 h in 6-DMAP followed by 7 h in CR2 aa medium plus with 2.5% fetal calf serum (FCS; Nutricell, Campinas, Brazil), both supplemented with 50 nM trichostatin A (Sigma); NT-CONT, zygotes were cultured in the same described conditions without thichostatin A supplementation. In vitro-fertilized embryos (IVF group) were used as a calibrator for relative transcript quantification. Embryos from the 3 groups were cultured in CR2 aa supplemented with 2.5% FCS under 5% CO2, 5% O2 and 90% N2 at 38.5°C. At 168 h postactivation, the embryos were rapidly frozen in liquid nitrogen. Pools of 10 blastocysts for each group were subject to RNA extraction and reverse transcription, in which cDNA was amplified by real-time PCR using the β-actin and GAPDH genes as endogenous references. The transcripts analysed encode high mobility group N1 (HMGN1), peroxiredoxin 1 (PRDX1), octamer-binding protein 4 (OCT4), insulin-like growth factor 1 and 2 receptors (IGF1r and IGF2r), glucose transporter 1 and 5 (GLUT1 and GLUT5), histone acetyltransferase (HAT) and heat shock protein 70.1 (HSP70) genes. Results were analysed by a pair-wise fixed reallocation randomization test using the REST software v.2. Data from NT-TRICHO and NT-CONT were compared with the IVF group and between themselves. The relative abundance of HSP70, PRDX1, IGF2r and HMGN1 transcripts was higher (P < 0.05) in NT-TRICHO compared with the IVF group and no difference was detected for the other transcripts. In the NT-CONT group, the relative abundance of IGF2r and HAT was higher (P < 0.05), whereas IGF1r and OCT4 were lower (P < 0.05) compared with IVF embryos. When data from NT-TRICHO and NT-CONT were compared, a higher amount (P < 0.05) of stress-associated transcripts (HSP70 and PRDX1) were found in NT-TRICO blastocysts. These results suggest that although trichostatin A may improve chromatin remodeling, alterations on gene expression still persist in bovine somatic cell nuclear-transferred blastocysts in comparison with IVF embryos. Financial support: Embrapa Project 01.07.01.002, CNPq 403019/2008–7 and Fapemig.

137 DIFFERENTIAL GENE EXPRESSION OF IN VITRO-MATURED BOVINE OOCYTES WITH OR WITHOUT A POLAR BODY

Oocyte competence is associated with the amount of transcripts stored in the ooplasm and oocyte ability to extrude polar bodies (PB). To our knowledge, however, no data comparing mRNA levels between bovine oocytes maturated in vitro with or without PB are available. The aim of the present study was to compare the relative abundance of transcripts of glucose transporter 1 (GLUT1), insulin-like growth factor 1 receptor (IGF1R), insulin-like growth factor 2 receptor (IGF2R), growth differentiation factor-9 (GDF9) and aquaporin 3 (AQP3) genes between oocytes with and without PB (PB and NPB groups, respectively) following in vitro maturation. Immature bovine oocytes were obtained by follicular aspiration and matured in TCM-199 (Gibco Life Technologies, New York, NY, USA) containing 10% of oestrus cow serum and 20 μg mL–1 of FSH (Pluset, Serono, Italy) for 24 h under 5% CO2 in air at 38.5°C. Subsequently, oocytes were visually classified according to the presence or absence of PB and then denuded and rapidly frozen in liquid nitrogen. Three pools of 10 oocytes for each group were subjected to total RNA extraction using the RNeasy Micro Kit (Qiagen GmbH, Hilden, Germany) according to the manufacturer's instructions and treated with DNase. Reverse transcription and cDNA amplification were performed using the TransPlex Complete Whole Transcriptome Amplification Kit (WTA2, Sigma, St. Louis, MO, USA) according to the manufacturer's instructions. Relative abundance of the target transcripts was performed by quantitative RT-PCR (Applied Biosystems Prism 7300 Sequence Detection Systems, Foster City, CA, USA) using a mixture of SYBR® Green PCR Master Mix (Applied Biosystems), 200 ng of cDNA, nuclease-free water and specific primers for each reaction. Expression of the β-actin gene was used as an endogenous reference. Relative gene expression analysis was performed using the software REST© 2005 using the Pair Wise Fixed Reallocation Randomization Test©. The relative expression values are presented as mean ± standard error. The relative abundance of GLUT1 (0.81 ± 0.07), IGF2R (0.72 ± 0.07) and GDF9 (0.82 ± 0.10) genes was lower (P < 0.05) for NPB oocytes. There was no difference (P > 0.05) in relative abundance between PB and NPB groups for the other genes. The results suggest that the amount of some transcripts stored in the matured ooplasm is associated with the presence of PB. The authors acknowledge FAPEMIG, CNPq and Innovation Network Project on Animal Reproduction (01.07.01.002).

169 THE RELATIONSHIP BETWEEN OOCYTE RECOVERY AND EMBRYO PRODUCTION IN BOS INDICUS

The ovarian follicular population has been used as a parameter to evaluate fertility and also the potential of donors undergoing assisted reproductive procedures in both human medicine and animal practice. There is a high correlation between follicular population and oocyte recovery by ovum pickup (OPU), but the relationship between oocyte recovery, embryo production and pregnancy rates may not be fully understood. The aim of the present study was to evaluate whether the conversion rate of oocytes to embryos and further pregnancies could be positively related to the number of cumulus–oocyte complexes (COC) recovered after OPU in cattle. For this purpose, records of 626 OPU sections from 251 nonlactating Gyr cows (dairy Zebu breed) were analysed. The animals had a good body condition score, were kept in a good feeding pasture (Brachiaria spp.) and were supplemented with corn silage and a mixture of corn, soybeans and vitamin and minerals, according to their nutritional requirements. For each ovarian aspiration, the ovarian follicular wave was previously synchronized with an auricular implant (Norgestomet-Crestar®), IM injections of 2 mg of oestradiol benzoate (Gonadiol®) and 0.25 mg of D-cloprostenol (Sincrocio®). The OPU procedures were performed using an ultrasound device (Aquila Vet, Esaote, São Paulo, Brazil) equipped with a vaginal sector 7.5-MHz probe, disposable 20 G needles and a vacuum pressure of 80 mmHg. The cows were ranked in quartiles regarding the total number of COC recovered. To reduce bias related to the eventual fluctuation of OPU results, for the present analysis the authors used only the recorded OPU session of each cow with the highest number of COC recovered. Viable COC were fertilized with sex-sorted (X) semen of Gyr bulls previously tested for in vitro embryo production. Conversion rates (%) of the total and viable oocytes to embryos, viable oocytes to pregnancy and embryo to pregnancy were evaluated for each quartile. Differences between the first and fourth quartiles were accessed by Fisher's exact test. In the 251 OPU, 4246 total and 3173 viable COC were recovered, resulting in the production of 1001 embryos (31.5%) and 453 pregnancies (45.3%). The cows ranked in the first, second, third and fourth quartiles produced >30 (41.6 ± 10.6), 21 to 30 (25.2 ± 3.0), 12 to 20 (15.9 ± 2.6) and <12 (6.7 ± 3.1) total oocytes. The average viable oocyte (29.1 ± 11.0, 18.1 ± 5.3, 11.1 ± 3.7 and 4.5 ± 2.7, respectively) and embryo production (8.6 ± 5.7, 5.2 ± 3.6, 3.8 ± 2.8 and 1.8 ± 1.8, respectively) were different (P < 0.0001) among all quartiles. Pregnancy rates, however, did not differ (46.0, 44.9, 43.9 and 45.6%, respectively; P > 0.05). Interestingly, the conversion rates (viable oocytes to embryos and viable oocytes to pregnancies) were higher (P < 0.0001 and 0.002) in cows from the last quartile (51.1 and 31.9%) compared with those from the first quartile (23.7 and 14.7%). In conclusion, the number of COC recovered by OPU (and consequently the ovarian follicular count) can further predict the total number of embryos and pregnancies produced, but it is not directly related to the oocyte development potential. Biotran and Fapemig Project CVZ APQ 01654/09 and BPD 0007/10.

209 EFFECT OF HEAT STRESS ON DEVELOPMENT OF IN VITRO-FERTILIZED AND PARTHENOGENETIC BOVINE EMBRYOS

Heat stress has been a challenge for bovine reproduction in tropical and subtropical environments. Although the role of the oocyte in thermotolerance has been studied, little attention has been paid to the contributions of sperm to embryo resistance to heat shock. The current study aimed to evaluate the development of fertilized and nonfertilized (parthenogenetic) bovine embryos undergoing heat stress during the pre-implantation stage. Cumulus–oocyte complexes obtained from ovaries collected from Bos indicus × Bos taurus crossbred cows at slaughter were in vitro matured with TCM-199 supplemented with 20 μg mL–1 of FSH, under 5% CO2 at 38.5°C for 24 h. Afterward, oocytes were randomly allocated into 2 groups: 1) IVF and 2) PART (chemical activation for parthenogenesis induction). In vitro-fertilized oocytes were cultured with 2.0 × 106 Holstein sperm mL–1 in Fert-TALP medium supplemented with heparin, for 20 h. For chemical activation, oocytes were activated with calcium ionomycin for 4 min, followed by 6-DMAP for 4 h, both in CR2aa medium supplemented with 0.1% BSA. Presumptive IVF (n = 1 262) or PART (n = 1 206) zygotes were denuded by vortexing and cultured in CR2aa medium with 2.5% of FCS under 5% CO2, 5% O2, and 90% N2 at 38.5°C. At 44 h post-insemination or chemical activation, embryos were exposed to 38.5 or 41°C for 12 h in an atmosphere of 5% CO2, 5% O2, and 90% N2. After that, embryos were cultured at 38.5°C under 5% CO2, 5% O2, and 90% N2 until Day 8 post-insemination. Blastocyst rates were evaluated at Day 7 and Day 8 post-insemination and were calculated based on the total number of presumptive zygotes. Blastocysts at 192 h post-insemination or activation were fixed and permeabilized for TUNEL assay (DeadEndTM Florimetric TUNEL System, Promega, Madison, WI) according to the manufacturer’s instructions. The effect of heat stress was compared within groups (IVF or PART) and the data were analysed by ANOVA. As expected, heat stress reduced the blastocyst rate of IVF embryos at Day 7 (24.3 ± 2.0% and 17.4 ± 2.2% for nonstressed and stressed IVF embryos; P < 0.05) and at Day 8 (32.4 ± 1.9% and 23.0 ± 2.1% for nonstressed and stressed IVF embryos; P < 0.01). However, the effect of heat stress on blastocyst rate of PART embryos was observed only at Day 8 post-insemination (30.0 ± 1.7% and 22.6 ± 2.0% for nonstressed and stressed PART embryos; P < 0.05), with no difference in blastocyst rate at Day 7 (21.6 ± 1.5% and 18.2 ± 1.8% for nonstressed and stressed PART embryos; P > 0.05). There was no difference in total cell numbers between nonstressed and stressed IVF or PART embryos. Apoptosis cell numbers and the apoptotic cell index were higher (P < 0.05) for stressed IVF (18.45 ± 1.24 and 0.16 ± 0.00) and PART (16.40 ± 5.20 and 0.17 ± 0.00) embryos than for nonstressed IVF (13.70 ± 0.75 and 0.13 ± 0.00) and PART (14.15 ± 0.86 and 0.13 ± 0.00) embryos. In conclusion, heat stress can induce apoptosis in both IVF and PART embryos, but its effect on pre-implantation development may occur at earlier stages in IVF embryos when compared with PART embryos. Financial support from Fapemig and CNPq.

229 EVALUATION OF OOCYTE QUALITY RECOVERED FROM Gir BREED COWS WITH SYNCHRONIZED FOLLICULAR WAVE ON IN VITRO EMBRYO PRODUCTION

Recent data reveal that approximately 80% of bovine embryos produced in vitro worldwide are from (Brazil J. H. M. Viana, personal communication). Adoption of this biotechnology by Brazilian producers might be attributed to particularities of the Bos indicus subspecies. Zebu breeds provide 2 to 3 times more viable oocytes than Bos taurus breeds per ovum pickup (OPU) session. This work aimed to evaluate the quality of cumulus–oocyte complexes (COC) retrieved from Gir breed cows (B. indicus) by OPU with a synchronized follicular wave and subjected to an in vitro embryo production (IVP) technique. All COC were obtained by OPU of 14 Gir cows performed every 14 days. There were 4 OPU sessions, preceded by synchronization of the follicular waves. Wave synchronization was achieved by an injection of 2 mg of oestradiol benzoate followed by the insertion of a norgestomet implant that stayed in place for 5 days. On Day 5, follicles of 2 to 8 mm were aspirated. The oocytes recovered were distributed according to classification: Group 1, with ≥3 cumulus cell layers and homogeneous or slightly heterogeneous cytoplasm (n = 314); and Group 2, ≤2 cumulus cells layers and slightly or coarsely granulated cytoplasm (n = 236). Oocytes from both groups were followed to in vitro maturation–IVF–fertilization–in vitro culture. Two (Day 2) and 8 (Day 8) days after the beginning of fertilization, the cleavage and blastocyst rates were measured, respectively. The statistical analyses were performed using a chi-square test (P < 0.05). The mean cleavage rates observed were 72.93 and 69.07% (not significant), whereas the mean blastocyst rates were 37.90 and 17.80%, and were significantly different for Groups 1 and 2, respectively. The results suggest that the morphology of oocytes (number of cumulus cell layers and cytoplasm homogeneity) is a strong indicator of the in vitro developmental capacity of oocytes recovered from Gir cows with synchronized follicular waves, although we did not observe compromised cleavage rates. Financial support was provided by Fapesp/Fapemig/CNPq/Embrapa. Epamig/Faz. Calciolândia/Nutricell–Nutrientes Celulares is acknowledged.

323 EFFICIENCY OF CLOPROSTENOL-INDUCED LUTEOLYSIS IN SUPEROVULATED COWS

The induction of multiple ovulations is a key procedure for in vivo embryo production. Many corpora lutea (CL) are developed, resulting in abnormally high progesterone concentrations. Luteolysis induction by prostaglandin F2α and its analogues is well described in cows bearing one or few, but not multiple, CL, as occurs after superovulation. The objective of the first experiment was to compare the efficacy of a single prostaglandin F2α treatment on inducing luteolysis in embryo donors immediately after flushing (D7, N = 24) or 4 days later (D11, N = 22). Holstein cows were superovulated with 400 IU of FSH following standard procedures. Embryo flushing was performed 7 days after AI, and cows were randomly allocated into 2 groups to receive either a 0.5 mg of sodium cloprostenol IM treatment immediately after flushing (D7 group) or the same treatment 4 days later (D11 group). Occurrence of luteolysis was monitored by plasma progesterone concentrations (P4), measured by radioimmunoassay in blood samples taken at 4-h intervals. There was no difference in P4 before treatment between D7 and D11 groups (28.6 ± 5.2 v. 36.4 ± 7.4 ng mL–1, respectively; P > 0.05). Although cloprostenol caused a remarkable decline in P4 48 h after treatment in both groups (1.8 ± 0.3 and 1.6 ± 0.4 ng mL–1 for D7 and D11 groups, respectively; P < 0.05), P4 continued decreasing in D11 cows thereafter, remaining smaller than 1 ng mL–1 up to 196 h after treatment, whereas in D7 cows, there was no further reduction in P4. Luteolysis (P4 <1 ng mL–1) was observed in all D11 cows, but failed in 11 of 20 (55%) D7 cows, in which P4 increased after the initial cloprostenol-induced decrease. The second experiment compared luteolysis in superovulated v. nonsuperovulated cows. Non-superovulated (control group, CG, N = 8) and superovulated cows (SOV, N = 6) received a single dose of sodium cloprostenol IM (0.5 mg) on day 11 after oestrus. Morphological and functional luteolysis were monitored daily by ovarian ultrasonography and P4 analysis; also, plasma LH was measured in blood samples taken every 20 min for 1 h, during 5 days. Individual CL size was smaller (1.8 ± 0.1 v. 3.5 ± 0.4 cm2) but total luteal tissue was greater (29.8 ± 7.0 v. 3.5 ± 0.4 cm2; P < 0.05) in SOV than in CG. A considerable decrease in P4 occurred in both groups 24 h after treatment (from 51.1 ± 12.9 to 5.1 ± 0.9 ng mL–1 in SOV and from 5.9 ± 0.6 to 1.1 ± 0.1 ng mL–1 in CG); however, SOV cows did not reach P4 values similar to CG until 96 h after treatment (0.9 ± 0.3 v. 0.4 ± 0.2 ng mL–1, respectively; P > 0.05). There was no difference in initial LH values between SOV and CG (1.5 ± 0.1 and 1.5 ± 0.1 ng mL–1; P > 0.05), but the slower decrease in P4 in the SOV group prevented LH from increasing up to 96 h after luteolysis induction, whereas mean LH values increased (P < 0.05) in CG after 24 h. In conclusion, luteolysis failure may occur when cloprostenol is given at the day of flushing (7 days after AI) in superovulated cows. In addition, luteolysis induction on day 11 after SOV is efficient, but the initial high progesterone concentration results in a slower rate of P4 decrease to basal levels. The authors acknowledge CNPq and FAPEMIG Project CVZ AQP 01654/09.

31 DEVELOPMENT AND APOPTOSIS IN BOVINE CLONED EMBRYOS RECONSTRUCTED WITH OOCYTES COLLECTED BY REPEATED OVUM PICKUP SESSIONS OR FROM SLAUGHTERED COW OVARIES

The oocyte has important components for nuclear reprogramming and its cytoplasmic background may influence the somatic cell nuclear transfer success. The current study attempted to evaluate the competence of cytoplasm from oocytes recovered by repeated ovum pickup (OPU) in living cows (OPU group) or obtained from ovaries collected at slaughterhouse from unknown source crossbred cows (SH group) to produce nuclear-transferred bovine embryos. For the OPU group, oocytes were recovered from 4 Bos indicus × Bos taurus crossbred cows in 4 repeated OPU sessions. Oocytes of OPU and SH groups were matured in vitro for 17 to 18 h, denuded and exposed to Hoechst 33342 (Sigma, St. Louis, MO, USA) and cytochalasin (Sigma) before enucleation. Embryos of OPU (n = 100) and SH (n = 105) groups were reconstructed with somatic cells from adult Gyr (Bos indicus) cow, fused with double electric pulse of 2.4 kV cm–1 for 30 μs and activated with ionomycin (Sigma) and 6-DMAP (Sigma). Embryos were cultured in CR2aa medium supplemented with 2.5% fetal calf serum (Nutricell, Campinas, Brazil) under 5% CO2, 5% O2, and 90% N2 at 38.5°C. Cleavage and blastocyst rates were evaluated at 72 h and 168 h post-activation, respectively. Blastocysts at 168 h post-activation were fixed and permeabilized for TUNEL assay (DeadEnd™ Fluorimetric TUNEL System, Promega, Madison, WI, USA), according to the manufacturer instructions. IVF bovine blastocysts (IVF group; n = 245) obtained with oocytes of slaughtered cows were used as control group. Fusion, cleavage, and blastocyst rates were analysed by chi-square test and total cell number, apoptotic cell number, and apoptotic cell index (calculated by dividing the apoptotic cell number by total cell number) were analysed by ANOVA. There were no differences (P > 0.05) in fusion (71.0% and 61.0%), cleavage (74.6% and 78.1%) or blastocyst (32.3% and 31.2%) rates between OPU and SH groups, respectively, but both groups presented greater (P < 0.05) blastocyst rates than the IVF group (15.1%). Total cell number (80.66 ± 5.36 and 82.10 ± 4.79), apoptotic cell number (12.66 ± 3.20 and 15.60 ± 3.04), and apoptotic cell index (0.15 ± 0.03 and 0.20 ± 0.04) were also similar (P > 0.05) between OPU and SH groups, respectively. However, apoptotic cell number (7.40 ± 0.93) and apoptotic cell index (0.07 ± 0.01) were lower (P < 0.05) in the IVF group than the SH group and similar (P > 0.05) to the OPU group. In conclusion, oocytes cytoplasm from both groups (OPU and SH) have the same potential to produce nuclear-transferred bovine embryos but only blastocysts from the OPU group present apoptosis levels similar to its in vitro-fertilized counterpart. Financial support: Fapemig and CNPq.

172 REUSE OF AUTOCLAVED INTRAVAGINAL PROGESTERONE DEVICE TO ESTROUS SYNCHRONIZATION IN TOGGENBURG GOATS IN THE BREEDING SEASON

Reusing intravaginal devices represents an important alternative to reduce costs; however, this practice may increase disease transmission. The aim of this study was to evaluate the efficacy of reusing autoclaved intravaginal progesterone devices for oestrous synchronization in Toggenburg goats in the breeding season was studied. This study was done in March and April of 2009, in Piau, MG, Brazil (latitude 21°35′ and longitude 43°15′). Sixty-seven Toggenburg nulliparous (n = 17; 35.3 ± 5.4 kg and 3.3 ± 0.2) and pluriparous (n = 50; 52.9 ± 9.8 kg and 3.4 ± 0.3) goats were assigned according to weight and body condition score (BCS, 1 to 5 scale) into 3 treatments. Animals received new devices (n = 25; 48.2 ± 11.5 kg and BCS 3.4 ± 0.3) containing 0.33 g of progesterone (Eazi-Breed CIDR®, Pfizer Animal Health, São Paulo, Brazil) or autoclaved (121°C, 1 atm, 15 min) devices previously used for 6 days (n = 23; 48.3 ± 13.0 kg and 3.5 ± 0.3) or 12 days (n = 22; 48.2 ± 11.0 kg and 3.4 ± 0.3). All goats received 5 mg dinoprost (Lutalyse®, Pfizer Animal Health) in the vulvar submucosa on the day of CIDR insertion (Day 0) and 200 IU eCG (Novormon 5000®, Sintex Indústria Bioquímica, Buenos Aires, Argentina) 1 day before CIDR removal, also in the vulvar submucosa. The CIDR were removed on day 6, and goats were bred twice daily with fertile bucks at oestrous onset and 24 h later if they were still in oestrus. Parametric variables were analysed by ANOVA and SNK tests by the SAEG® program. Nonparametric variables were analysed using the chi-square test by the BioEstat® program. The results are described as mean ± SD. Oestrous response and conception rates did not differ (P > 0.05) among goats treated with the new devices (75.0; 54.2%) or those previously used for 6 (81.8; 50.0%) or 12 days (71.4; 47.6%), respectively. No differences were detected between nulliparous (82.3; 52.9%) and pluriparous (72.0; 50.0%) goats. The interval from device removal to oestrus and duration of oestrus were not different (P > 0.05) among animals receiving a new device (39.3 ± 15.8; 30.7 ± 16.6 h) or previously used devices for 6 (32.7 ± 11.5; 31.8 ± 7.3 h) or 12 day (40.8 ± 20.7; 32.8 ± 13.2 h) treatments, respectively, or between nulliparous (41.6 ± 14.9; 30.9 ± 13.9 h) and pluriparous (35.6 ± 16.8; 32.1 ± 12.8 h) goats. Since no differences were detected in the evaluated variables among goats receiving reused autoclaved devices or new ones, it can be suggested that the autoclaving process did not affect the efficiency of reusing intravaginal progesterone devices for oestrous synchronization in Toggenburg goats in the breeding season. Probably, P4 concentrations in goats receiving reused autoclaved devices reached at least minimum concentrations to promote oestrous response, since a non-treated group would not show oestrus in this level of synchronization as in goats in this study. This technique can be a simple and valuable tool to reduce sanitary risks of disease transmission without altering fertility in goats. CNPq, Pfizer Animal Health, Embrapa Goats, and Sheep Research, CAPES.

257 DIFFERENCES BETWEEN BOS TAURUS AND BOS INDICUS EMBRYOS: TRANSCRIPTS AMOUNTS

The Zebu breeds (Bos indicus) are different from European breeds (Bos taurus) in some aspects of their reproductive physiology, including follicle recruitment, number of follicular waves, and oocyte ultrastructure. On the other hand, embryos produced in vivo and in vitro show morphological and developmental differences, which can be related to culture environment. The aim of this study was to evaluate the effect of breed (Gyr v. Holstein) within embryo production system (in vivo and in vitro), as well as effect of production systems within breeds on relative abundance of transcripts related to formation, survival, and subsequent development of blastocysts, such as those involved in water and small solutes transport (Aquaporins 3 and 11), blastocoel formation (Na+/K+-ATPase a1 and |52), and cellular stress response (Peroxiredoxin 1). For in vivo embryo production, donors were superstimulated with FSH and inseminated, and embryos were recovered 7 days after AI. For in vitro embryo production, oocytes recovered by ovum pickup were in vitro matured and fertilized and then cultured for 7 days in culture medium under 5% CO2 at 38.5°C. For each group, blastocysts (n = 15) distributed in 3 pools were used for RNA extraction (RNeasy MicroKit, Qiagen, Valencia, CA, USA), followed by RNA amplification (Messageamp II amplification kit, Ambion-Applied Biosystems, Foster City, CA, USA) and reverse transcription (SuperScript III First-Stand Synthesis Supermix, Invitrogen, Carlsbad, CA, USA). The cDNA were submitted to real-time PCR, using the H2a gene as endogenous control, and analyzed by REST© software. To evaluate breed effect within the production systems, 2 comparisons were performed: (1) in vivo: Gyr v. Holstein and (2) in vitro: Gyr v. Holstein, considering Holstein data as 1.00. To evaluate production system effect within breeds, 2 comparisons were performed: (1) Gyr: in vivo v. in vitro and (2) Holstein: in vivo v. in vitro, considering in vivo produced embryo data as 1.00. The results are shown as mean ± SEM. For in vivo comparison between breeds, Aquaporin 3 (1.66 ± 0.77), Na+/K+-ATPase a1 (1.61 ± 0.56), and Peroxiredoxin 1 (1.61 ± 0.66) were up-regulated (P < 0.05) in Gyr embryos when compared with Holstein embryos, whereas for in vitro comparison, no differences (P > 0.05) were found. For comparisons between production systems within breeds, only Peroxiredoxin 1 (0.31 ± 0.39) was down-regulated (P < 0.01) in in vitro produced Gyr embryos when compared with in vivo counterparts. No differences (P > 0.05) were found between production systems for the Holstein breed. In conclusion, these data suggest that there is a difference on gene expression between Bos taurus and Bos indicus blastocysts, but such difference between breeds can be attenuated by the in vitro production system, indicating an embryo adaptation to the in vitro culture conditions. The data also suggest that the in vitro production system can influence the amount of transcripts in Gyr embryos. Other genes should be evaluated for a better understanding of these differences. Financial support was provided by CNPq and FAPEMIG.

216 DINOPROST ADMINISTRATION, PERIOD OF OVULATION, AND OVULATORY FOLLICULAR SIZE ON DAYS FOUR TO SIX OF ESTROUS CYCLE IN EWES

The aim of this study was to evaluate the effects of 2 doses of dinoprost at the time of ovulation on Days 4 to 6 of the estrous cycle in ewes. The experiment was conducted in the city of Piau (Minas Gerais, Brazil) from July to August 2008 during the local no-breeding season. Twenty-four ewes with body condition score 3.0 ± 0.75 were used for this experiment. The estrous cycle was synchronized with intravaginal releasing devices containing 0.33 g of progesterone for 6 days (Eazi-Breed CIDR®, Pfizer Animal Health, São Paulo, Brazil), and 12.5 mg of dinoprost (Lutalyse®, Pfizer do Brasil Saúde Animal, São Paulo, Brazil) laterovulvar plus 300 IU of eCG 24 h before device removal. Animals were monitored by transrectal ultrasonography every 8 h and subjected to 5 or 10 mg of dinoprost on Days 4, 5, or 6 of the cycle. Results were submitted to ANOVA and Tukey test, using all tests at the 95% confidence interval (SAEG program, Funarbe, Viçosa, Brazil). Data were reported as percentage or mean ± SD. The period from device removal to ovulation was 48.0 ± 7.07 h. The 5-mg dinoprost dose evoked similar (P > 0.05) results for Days 4, 5, and 6 regarding the time of ovulation after luteal gland regression induction [71.3 ± 28.6, 71.46 ± 30.4, and 68.2 ± 29.2 h for Days 4 (n = 4), 5 (n = 4), or 6 (n = 4), respectively] and follicle size (6.48 ± 0.34, 6.41 ± 0.35, and 6.5 ± 0.32 mm for Days 4, 5, and 6, respectively) at the time of ovulation. In animals that received 10 mg of dinoprost, the time of ovulation was affected (P ≤ 0.05) by Day of treatment [71.3 ± 27.6, 68.3 ± 30.6, and 64 ± 29.2 h for Days 4 (n = 4), 5 (n = 4), and 6 (n = 4), respectively]. However, there was no effect of the 10 mg on follicle size at ovulation (6.48 ± 0.34, 6.41 ± 0.35, and 6.3 ± 0.33 mm for Days 4, 5, and 6, respectively). There was no difference (P ≥ 0.05) on the size of ovulatory follicle(s) among animals with 1 (n = 4, 4, and 1 for Days 4, 5, and 6, respectively), 2 (n = 3, 3, and 4 for Days 4, 5, and 6, respectively), and 3 (n = 1, 1, and 3 for Days 4, 5, and 6, respectively) ovulations. The difference in the interval from luteal gland regression to ovulation in animals that received 10 mg of dinoprost on Day 6 of the estrous cycle suggests a higher sensitivity of corpora lutea at that moment. Results showed that both doses of dinoprost were capable of inducing early luteal gland regression; this fact supports the use of short-term protocols for the induction of estrus in ewes. Pfizer Brazil, CNPq, FAPEMIG.

440 EVALUATION OF FOLLICULAR GROWTH AFTER EXOGENOUS STIMULATION IN MICE USING ULTRASOUND BIOMICROSCOPY

Real-time follicular dynamics studies have often been restricted to large animals because of the resolution of ultrasound equipment available. The recent advances in image technology, including significant gains in spatial resolution, allowed these evaluations to be performed in small rodents, which are important models to understand folliculogenesis. The aim of this study was to evaluate exogenous stimulated follicular growth in mice using a high resolution ultrasound. Female mice (n = 15) received a 5 IU i.p. injection of eCG (Vetecor®, Calier) and 48 h later a 5 IU injection of hCG (Novormon®, Schering-Plough), and were mated thereafter. In experiment 1, animals (n = 7) were anesthetized with ketamin/xilazin solution and evaluated at 3, 9, 15, 21, 27, 33, 45, and 51 h after eCG injection. The ovaries were identified with ultrasound biomicroscopy (UBM, Vevo 660®, Visual Sonics, Toronto, ON, Canada) coupled with real-time micro-visualization probe (RMV 707b), and the follicular population was measured, quantified, and classified into small follicles (≤449 μm) and large follicles (≥450 μm). The number of small follicles decreased (P < 0.05) from 30.44 ± 15.91 to 14.79 ± 7.23, and the number of large follicles (≥450 μm) increased from 0.36 ± 0.74 to 4.21 ± 4.25. For both size classes, however, statistical differences only occurred at 45 h after eCG; that is, close to the moment of hCG injection. In experiment 2, animals (n = 8) were evaluated every 2 h beginning 4.5 h after hCG to check for ovulations. The largest follicles achieved a mean maximum size of 596.7 ± 106.0 μm, 5.8 ± 2.3 h after hCG application. In 5 animals, large follicles were observed at 2 distinct moments, 5.0 ± 1.2 h and 10.4 ± 1.0 h after hCG, respectively. Results suggest that the later stages of follicular growth in mice are only achieved a few hours before ovulation, and that ovulations induced by hCG are not synchronized. Financial suport: Fapemig, CBTC São Rafael, CNPq.