Comparison of reproductive management programs for submission of Holstein heifers for first insemination with conventional or sexed semen based on expression of estrus, pregnancy outcomes, and cost per pregnancy

Our objective was to evaluate reproductive management programs for submission of Holstein heifers for first insemination with conventional or sexed semen. In experiment 1, nulliparous Holstein heifers (n = 462) were submitted to a 5-d progesterone-releasing intravaginal device (PRID)-Synch protocol [d 0, GnRH + PRID; d 5, PGF_2α - PRID; d 6, PGF_2α; d 8, GnRH + TAI] and were randomly assigned for PRID removal on d 5 or 6 of the protocol followed by timed artificial insemination (TAI) with conventional semen. Delaying PRID removal decreased early expression of estrus before scheduled TAI (0.9 vs. 12.2%), and pregnancies per AI (P/AI) did not differ between treatments. In experiment 2, nulliparous Holstein heifers (n = 736) from 3 commercial farms were randomized within farm to 1 of 3 treatments for first AI with sexed semen: (1) CIDR5 [d -6, GnRH + controlled internal drug release (CIDR); d -1, PGF_2α - CIDR; d 0, PGF_2α; d 2, GnRH + TAI]; (2) CIDR6 (d -6, GnRH + CIDR; d -1, PGF_2α; d 0, PGF_2α - CIDR; d 2, GnRH + TAI); and (3) EDAI (PGF_2α on d 0 followed by once-daily estrous detection and AI). Delaying CIDR removal decreased early expression of estrus before scheduled TAI (0.004 vs. 27.8%); however, CIDR5 heifers tended to have more P/AI at 35 (53 vs. 45 vs. 46%) and 64 (52 vs. 45 vs. 45%) days after AI than CIDR6 and EDAI heifers, respectively. Overall, CIDR5 and CIDR6 heifers had fewer days to first AI and pregnancy than EDAI heifers which resulted in less feed costs than EDAI heifers due to fewer days on feed until pregnancy. Despite greater hormonal treatment costs for CIDR5 heifers, costs per pregnancy were $16.66 less for CIDR5 than for EDAI heifers. In conclusion, delaying PRID removal by 24 h within a 5-d PRID-Synch protocol in experiment 1 suppressed early expression of estrus before TAI, and P/AI for heifers inseminated with conventional semen did not differ between treatments. By contrast, although delaying CIDR removal by 24 h within a 5-CIDR-Synch protocol in experiment 2 suppressed early expression of estrus before TAI, delaying CIDR removal by 24 h tended to decrease P/AI for heifers inseminated with sexed semen. Further, submission of heifers to a 5-d CIDR-Synch protocol for first AI tended to increase P/AI and decrease the cost per pregnancy compared with EDAI heifers.

Effect of manipulating progesterone before timed artificial insemination on reproductive and endocrine outcomes in high-producing multiparous Holstein cows

Our objective was to evaluate the effect of manipulating progesterone (P4) concentrations before timed artificial insemination (TAI) on reproductive and endocrine outcomes in high-producing Holstein cows. Multiparous lactating Holstein cows (n = 80) were synchronized for first TAI using a Double-Ovsynch protocol and were randomly assigned to receive 25 mg of PGF_2α 1 d after the first GnRH treatment of the Breeding-Ovsynch protocol that included a once-used P4 insert (low-P4 group) or to receive 2 new P4 inserts during the Breeding-Ovsynch protocol (high-P4 group). Blood samples were collected thrice weekly from -10 to 32 d relative to TAI for all cows and from 32 to 67 d after TAI for pregnant cows and were analyzed for P4 and pregnancy-specific protein B (PSPB) concentrations. Expression of IFNτ-stimulated gene 15 (ISG15) was assessed in blood leukocytes 18 and 20 d after TAI. As expected, P4 concentrations were greater for high-P4 cows than for low-P4 cows from 3 to 8 d before TAI. Incidence of double ovulation was 3-fold greater for low-P4 cows than for high-P4 cows (33 vs. 10%), which resulted in more twin pregnancies 32 d after TAI for low-P4 cows than for high-P4 cows (29 vs. 0%). Low-P4 cows had larger preovulatory follicles at the last GnRH treatment of the Double-Ovsynch protocol and greater P4 concentrations than high-P4 cows after TAI. Relative expression of ISG15 mRNA 18 and 20 d after TAI was greater for low-P4 cows than for high-P4 cows and for pregnant cows than for nonpregnant cows. Overall, PSPB concentrations tended to be greater for low-P4 cows than for high-P4 cows, and pregnant cows had greater P4 concentrations than nonpregnant cows. In summary, cows with low P4 before TAI had increased preovulatory follicle diameter, PSPB concentrations, relative expression of ISG15 mRNA 18 and 20 d after TAI, double ovulations, and twinning compared with cows with high P4 before TAI. Increasing P4 before TAI may effectively decrease double ovulation and twinning in high-producing multiparous Holstein cows.

MALDI MS imaging investigation of the host response to visceral leishmaniasis

Mass spectrometry imaging (MSI) of animal tissues has become an important tool for in situ molecular analyses and biomarker studies in several clinical areas, but there are few applications in parasitological studies. Leishmaniasis is a neglected tropical disease, and experimental mouse models have been essential to evaluate pathological and immunological processes and to develop diagnostic methods. Herein we have employed MALDI MSI to examine peptides and low molecular weight proteins (2 to 20 kDa) differentially expressed in the liver during visceral leishmaniasis in mice models. We analyzed liver sections of Balb/c mice infected with Leishmania infantum using the SCiLS Lab software for statistical analysis, which facilitated data interpretation and thus highlighted several key proteins and/or peptides. We proposed a decision tree classification for visceral leishmaniasis with distinct phases of the disease, which are named here as healthy, acute infection and chronic infection. Among others, the ion of m/z 4963 was the most important to identify acute infection and was tentatively identified as Thymosin β4. This peptide was previously established as a recovery factor in the human liver and might participate in the response of mice to Leishmania infection. This preliminary investigation shows the potential of MALDI MSI to complement classical compound selective imaging techniques and to explore new features not yet recognized by these approaches.

Matrix-assisted laser desorption/ionization imaging mass spectrometry for the spatial location of feline oviductal proteins

With the purpose of identifying factors involved in early stages of embryo development in the domestic cat, matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) was used for the first time to describe the spatial localization of proteins in the oviducts of queens. Oviducts were obtained from two 2 and 4 years old cross-bred queens, divided into three segments, snap-frozen in liquid nitrogen and then stored at -80°C until use. Next, they were sectioned in a cryostat, fixed on ITO (indium tin oxide) conductive glass slides for MALDI-IMS and serial sections were collected on microscope slides for histology. As confirmed by histology, MALDI-IMS was able to show contrasting protein distributions in the oviductal infundibulum, ampulla and isthmus. Mass spectra were characterized by abundant ions of m/z 1,259, 4,939, 4,960 and 10,626, which have been tentatively attributed to keratin, thymosin β10, thymosin β4 and S100, respectively. Keratin and thymosins are involved in the biological response to tissue damage. S100 proteins are calcium-modulated proteins implicated in a variety of cellular activities, including cell differentiation and regulation of cell motility. These results suggest that protein composition differs between segments of the cat oviduct, which corresponds to morphological changes within these sections. Further functional studies could elucidate the effects of these proteins on feline reproductive physiology.

Defective secretion of Prostaglandin F2α during development of idiopathic persistent corpus luteum in mares

Five mares that developed idiopathic persistent corpus luteum (PCL) were compared with 5 mares with apparently normal interovulatory intervals (IOIs). Progesterone (P4) and a metabolite of prostaglandin F2α (PGFM) were assayed daily beginning on the day of ovulation (Day 0). Transition between the end of an initial progressive P4 increase and the beginning of a gradual decrease in P4 occurred on mean Day 6. The gradual decrease in P4 between Days 6 and 12 was less (approached significance, P < 0.06) in the PCL group than in the IOI group. The P4 concentration on Day 12 (before luteolysis in IOI group) was greater (P < 0.05) in the PCL group than in the IOI group. In a post hoc comparison, an interaction (P < 0.04) of group by day for Days 4 to 7 indicated that the end of the progressive increase in P4 was temporally associated with a transient increase in concentration of PGFM in IOI mares but not in PCL mares. Complete luteolysis (P4 < 1 ng/mL) occurred in the IOI mares on Days 13 to 15. Partial luteolysis (mean P4 decrease, 62%) occurred in 3 of the 5 PCL mares. Normalization to the day at the end of the most pronounced P4 decrease in the IOI mares and in the 3 PCL mares with partial luteolysis resulted in a day-by-group interaction (P < 0.05) for PGFM concentration. The interaction was partly from lower PGFM concentration on the day at the end of the pronounced P4 decrease in the 3 PCL mares than in the IOI mares. The peak of a transient PGFM increase and the day at the end of the most pronounced decrease in P4 were synchronized in each IOI mare but not in any of the 3 PCL mares. In the other 2 PCL mares, partial luteolysis did not occur, and a transient increase in PGFM was not apparent. Results tentatively indicated that the relationship between P4 and PGFM may be altered as early as Day 6 in PCL mares and supported the hypothesis that prostaglandin F2α secretion is defective in mares with idiopathic PCL.

Concentrations of progesterone, a metabolite of PGF2α, prolactin, and luteinizing hormone during development of idiopathic persistent corpus luteum in mares

In experiment 1, daily blood samples were available from Days 0 to 20 (Day 0 = ovulation) in mares with an interovulatory interval (IOI, n = 5) and in mares that developed idiopathic persistent corpus luteum (PCL, n = 5). The PCL was confirmed by maintenance of progesterone (P4) concentration until end of the experiment (Day 20). Significant interactions of group and day revealed the novel findings that luteinizing hormone (LH) was lower (P < 0.05) in the PCL group than that in the IOI group on Days 0 to 4, and prolactin was lower (P < 0.05) on Days 1, 4, 6, and 7. In experiment 2, treatment with a gonadotropin-releasing hormone antagonist (n = 6) significantly reduced LH on Days 1 to 6 compared with the controls (n = 6) but did not support the hypothesis that low LH during the postovulatory period increases the frequency of PCL. In experiment 3, P4, PGFM (a PGF2α metabolite), and prolactin concentrations on Days 12 to 20 from 2 reported experiments were combined to increase the number of mares with an IOI (n = 11) or a PCL (n = 11). An abrupt and complete decrease in P4 (luteolysis) began on Day 13 in the IOI group compared with a gradual and partial P4 decline after Day 12 in the PCL group. Concentrations of PGFM and prolactin were lower (P < 0.05) in the PCL group than those in the IOI group on the day at the end of the most pronounced decrease in P4. The PCL mares were subgrouped into those with an abrupt but incomplete P4 decrease (partial luteolysis; n = 5) at the expected time and those without partial luteolysis (n = 6). There were no significant differences between the 2 subgroups in concentrations of PGFM and prolactin, but on a tentative basis (P < 0.10), the concentration of PGFM seemed more focused on the day of the most pronounced decrease in P4 in the subgroup with partial luteolysis. Results for PCL compared with IOI indicated (1) postovulatory LH and prolactin were lower, (2) treatment to reduce postovulatory LH did not increase the incidence, and (3) both PGFM and prolactin were lower on the day of the most pronounced decrease in P4.

160 LIPIDOME SIGNATURES IN EARLY BOVINE EMBRYO DEVELOPMENT

Mammalian pre-implantation embryonic development is a complex, conserved, and well-orchestrated process involving dynamic molecular and structural changes. Understanding the membrane lipid profile fluctuation during this crucial period is fundamental to address cellular and molecular mechanisms governing embryogenesis. A full understanding of stage-specific lipid signatures in early bovine embryo development is, however, still lacking. The aim of the present work was to characterise stage-specific changes in lipid profiles during early bovine embryonic development. Immature oocytes were recovered from slaughterhouse-derived bovine ovaries and assigned among 5 in vitro developmental stages for lipid characterisation: immature oocytes, 2-cell embryos (32–40 h post-insemination), 8 to 16-cell embryos (72 h post-insemination), morulas (120 h post-insemination), and blastocysts (168 h post-insemination). Two different culture media were used for in vitro embryo production, SOFaaci medium supplemented with 2.5% of serum and serum-free SOF-BE1 medium. Cytoplasmic lipid droplets content and membrane phospholipids profiles for each development stage were assessed by lipid staining (Nile red; n = 5–9) and matrix-assisted laser desorption ionization as a mass spectrometry imaging (MALDI-MS; n = 5–9), respectively. For statistical analysis, univariate and multivariate models were used to compare lipid droplets content and membrane phospholipids profiles. Cytoplasmic lipid droplets content increased from minimum in the immature oocyte stage to maximum at the morula stage, followed by a sharp drop at the blastocyst stage (58.4 ± 10.5ac, 62.5 ± 9.4ac, 85.9 ± 8.2a, 148.3 ± 7.4b, 37.4 ± 9.9c of fluorescence intensity per embryo area, respectively, for immature oocyte, 2-cells, 8 to 16-cells, morulas, and blastocysts; abcP < 0.05). More cytoplasmic lipid droplets were detected in morulas and blastocyts cultured in SOFaaci than in SOF-BE1 (morulas, 162.6 ± 11.3 v. 137.1 ± 9.2 of fluorescence intensity per embryo area, respectively, P < 0.05; blastocysts, 49.9 ± 9.9 v. 20.7 ± 9.9 of fluorescence intensity per embryo area, respectively, P < 0.05). Characteristic dynamic changes of unsaturation level, acyl chain length and class composition (phosphatidylcholines, sphingomyelins, and phosphatidylethanolamines) of phospholipid profiles were observed during early embryo development. This study provides a comprehensive analysis, involving lipid staining and mass spectrometry evaluation, of stage-specific lipid signatures during bovine in vitro embryo development. These results may be useful for assessing the role of specific lipid species during important events of embryogenesis. Research was supported by CNPq, FAPESP, and FAPERGS.

Efficient green synthesis of bis(cyclic carbonate)poly(dimethylsiloxane) derivative using CO2 addition: a novel precursor for synthesis of urethanes

Poly(dimethyl siloxane), PDMS, with terminal cyclic carbonate groups was prepared by cycloaddition of carbon dioxide to epoxy rings using tetra alkyl-ammonium bromide as a catalyst under efficient and mild conditions.

164 RAPID IDENTIFICATION OF BACTERIA IN BOVINE SEMEN BY MATRIX-ASSISTED LASER DESORPTION/IONIZATION MASS SPECTROMETRY

Frozen bovine semen used in the IVF process can be a potential source of microorganisms that can prevent or disturb embryo development and cause issues with the sanitary certification for bovine embryo commercialization and export. Therefore, the aim of this work is to introduce a novel tool for the fast identification of the pathogens on the frozen semen based on the mass spectra of their ribosomal proteins analysed by matrix-assisted desorption/ionization-mass spectrometry (MALDI-MS). Thirty bovine semen samples, which were aliquots of commercial sealed straws used daily in the commercial IVF routine at In vitro Brasil Ltd. (Mogi Mirim, SP, Brazil), were used for this work. Fifty microlitres of semen were incubated in 10 mL of brain heart infusion broth (BHI) for 24 h at 37°C. If turbidity was observed, the bacterial cultures were submitted to bacterial extraction and mass spectrometric analysis according to Barreiro et al. (2010). The mass spectra were obtained using an AUTOFLEX MALDI TOF/TOF and were analysed with the database library MALDI Biotyper 3.0 software (Bruker Daltonik, Germany) at default settings. For each sample, the result was given by means of a log score with a maximum value of 3.0. In this study, only scores higher than 2.0 were considered, which provide confident species identification. The bacteria identified were Citrobacter freundii (2 samples), Stenotrophomonas maltophilia (4 samples), Enterobacter cloacae (6 samples) complex, Candida parapsilosis (2 samples), and Enterococcus mundtii (2 samples). Note that all the identified bacteria consistently match with the most common contaminants reported in literature for bovine frozen semen (Bielanskia et al. 2003). The capability of the technique to identify the bacteria without the ribosomal extraction (i.e. of bacteria pellets diluted in water and acetonitrile) was successful for the pellet of S. maltophilia, C. freundii, and E. cloacae complex with scores higher than 2.3, indicating a very high probability of the identification of the bacterial genus and the species. This can be explained by considering the capability of the mass spectrometric matrix to lyse the membrane of the bacteria and directly extract and then ionize the ribosomal proteins. In order to exclude the presence of a mixing of bacteria in the pellet, the colonies were properly isolated. The results matched with the ones obtained before the isolation. In order to confirm the MALDI-MS identification, the isolated bacteria from the bovine semen were also submitted to sequencing of region 16SrRNA. In conclusion, MALDI-MS technique was successfully applied for the identification of pathogens in the bovine semen. Experiments to evaluate the presence of microorganisms in media used for in vitro maturation, IVF, and in vitro culture of the bovine oocytes and embryos using this strategy are underway. This robust and fast approach is able to detect early contamination and allows prevention of economic losses and sanitary excellence in the bovine IVF process.

Correlation between susceptibility of primary HIV-1 isolates to autologous and heterologous neutralizing antibodies. Hospital Evandro Chagas AIDS Clinical Research Group

OBJECTIVE

To study the susceptibility of primary HIV-1 isolates towards autologous and heterologous neutralizing antibodies (NAb).

DESIGN

Blood was collected and primary HIV-1 isolated from individuals residing in Rio de Janeiro, Brazil, in all phases of disease.

METHODS

Primary HIV-1 isolates were incubated with autologous or heterologous plasma and neutralization of infection of freshly pre-stimulated normal human peripheral blood mononuclear cells was assayed in parallel to median infectious dose determinations in the absence of antibodies. Levels of HIV-1 p24 antigen were used for evaluation of viral neutralization.

RESULTS

Autologous neutralization (75%) was observed for 13 (52%) out of 25 of the primary HIV-1 isolates, and 15 (71%) out of 21 isolates were susceptible to 75% heterologous neutralization by at least one-half of the heterologous plasma tested. Primary HIV-1 isolates susceptible to autologous NAb showed a higher susceptibility towards neutralization by heterologous NAb than isolates that could not be neutralized by the autologous plasma (P = 0.049). The susceptibility of the primary HIV-1 isolates towards neutralization by heterologous NAb was significantly higher for isolates derived from men (P = 0.001), and for isolates obtained from individuals infected through homo-/bisexual risk behaviour in comparison with those infected through heterosexual HIV-1 transmission (P = 0.03).

CONCLUSIONS

Susceptibility of primary HIV-1 isolates to autologous and heterologous neutralization was significantly correlated, indicating that escape mutants may become resistant not only to autologous but also to heterologous NAb.