Effect of linseed feeding on blood metabolites, incidence of cystic follicles, and productive and reproductive performance in fresh Holstein dairy cows

Effect of a pre-calving injectable trace mineral supplement on white blood cell function in seasonally calving pastoral dairy cows

AIMS

To investigate the effect of injection of trace mineral supplement (TMS) 14-28 days before calving on white blood cell count (WBCC) and function, serum antioxidant capacity (SAC) and reactive oxygen species (ROS) in pasture-fed cattle after calving.

METHODS

On each of two South Island, seasonally calving, pastoral dairy farms,1 month before dry-off, a random sample of 150 multiparous cows predicted to calve within 7 days of the herd's planned start of calving (PSC) were stratified on individual somatic cell count, age, breed and expected calving date. On each farm, 14-24 days before PSC, 60 selected cows were randomly assigned for TMS (Zn, Mn, Se, Cu) injection, and 60 were controls. All 240 cows were contemporaneously injected with hydroxocobalamin, and controls with Se. Blood samples were collected pre-injection and 3, 12 and 40 days after calving. Phagocytic activity, count and proportion of neutrophils, lymphocytes and monocytes, WBCC, ROS, SAC were measured. Plasma concentrations of Se, Cu and glutathione peroxidase (GPx) were monitored from a random subset of animals. Differences attributable to TMS were estimated using mixed-multivariable Bayesian analysis, expressed as mean and highest density interval (HDI).

RESULTS

Three and 40 days after calving, TMS-treated cows had 0.36 (90% HDI = 0.00-0.77) x 109 and 0.25 (90% HDI = 0.00-0.55) x 109 fewer neutrophils/L. Neutrophils comprised 6 (90% HDI = 0-11)% and 4 (90% HDI = 0-8)% less of the WBCC, and the neutrophil count was 14 (90% HDI = 0-27)% and 9 (90% HDI = 0-18)% less than controls. However, 3 days after calving, there were 7 (95% HDI = 2-12)% more cells phagocytosing and 2,900 (95% HDI = 2,600-3,200) more bacteria ingested/cell. Twelve and 40 days after calving, TMS-treated cows had 0.65 (95% HDI = 0.17-1.17) x 109 and 0.28 (95% HDI = 0.00-0.59) x 109 more lymphocytes/L. Lymphocytes comprised 10 (95% HDI = 3-18)% and 5 (95% HDI = 0-9)% more of the WBCC, and the lymphocyte count was 30 (95% HDI = 11-51)% and 9 (95% HDI = 0-9)% more than controls. There were no meaningful differences in ROS, SAC, ROS/SAC, other white blood cells, or WBCC. Plasma Cu, Se and GPx concentrations were above recommended thresholds.

CONCLUSIONS

Pre-calving TMS injection was associated with differences in white blood cell population and function that may reduce the risk of disease.

ABBREVIATIONS

BHOB: Beta-hydroxybutyrate; GPx: Glutathione peroxidase; HDI: Highest density interval; MESF: Molecules of equivalent soluble fluorophore; OSi: Oxidative stress index; PSC: Planned start of calving; ROPE: Region of probable equivalence; ROS: Reactive oxygen species; SAC: Serum antioxidant capacity; THI: Temperature humidity index; TMS: Trace mineral supplement; WAIC: Widely applicable information criterion; WBCC: White blood cell count.

Different Lengths of Diet Supplementation with 10% Flaxseed Alter the Hormonal Profile and the Follicular Fluid Fatty Acid Content of Fattening Gilts

The effect of 10% dietary flaxseed fed for 3 and 6 weeks on serum hormone levels of fattening gilts, the fatty acid (FA) follicular fluid (FF) composition of small and large antral follicles, and the steroidogenesis and IGF-I secretion by isolated small antral follicles and their response to regulatory hormones (LH, FSH, IGF-I) was studied using immunoassay and gas chromatography analyses. Both supplemental periods increased levels of P4 and IGF-I in blood serum. A shorter period inhibited steroidogenesis (P4, T, E2) and IGF-I secretion by small antral follicles, which was associated with decreased levels of monounsaturated FAs (MUFA) and preferred n-6 polyunsaturated FA (PUFA) metabolism. A longer period stimulated hormone secretion at elevated levels of saturated FAs (SFA) at the expense of MUFAs and PUFAs preferring the n-3 PUFA metabolism. Out of ovarian regulators, only LH and IGF-I were able to alter the secretion of steroids and IGF-I by small follicles of fattening pigs fed a basal diet. The effect of flaxseed on the secretion of follicular hormones after both supplemental periods was altered by all regulatory hormones in a dose-dependent manner. The level of SFAs and PUFAs in FF of large follicles increased with the length of flaxseed feeding, suggesting the suppression of ovulation.

Feeding Flaxseed and Lupins during the Transition Period in Dairy Cows: Effects on Production Performance, Fertility and Biochemical Blood Indices

Flaxseed and lupin seed were offered as an alternative dietary approach in dairy cows, through the partial substitution of soybean meal. Milk production and fertility traits were investigated. A total of 330 animals were allocated into two groups, treated (n = 176) and control (n = 154). From each group, 30 animals were selected for hematological and cytological studies. The experimental feeding period lasted for 81 days (25 days prepartum and 56 days postpartum). The control ration (group C) contained corn, barley, soybean meal, rapeseed cake, corn silage and lucerne hay; whereas, in the treatment group (group T), 50% of the soybean meal was replaced by an equal mixture of flaxseed and lupins. The two rations were formulated to be isonitrogenous and isoenergetic. Milk samples were analyzed for chemical composition, somatic cell count (SCC) content and total colony forming units (CFU). Blood samples were collected, and serum was analyzed for non-esterified fatty acids (NEFA), acute phase proteins (haptoglobin and serum amyloid) and lipid oxidation indices, namely thiobarbituric-acid-reactive substances (TBARS) and catalase activity. To assess polymorphonuclear neutrophils (PMN) numbers, endometrial samples from each cow were collected on days 21 and 42. No difference was recorded between groups in milk yield (p > 0.05). In multiparous cows, NEFA (mMol/L) concentrations were significantly lower in group T than in group C on day 14 (p > 0.009) and on day 42 (p = 0.05), while no difference was detected in the group of primiparous cows. At all time points, serum TBARS and catalase values were similar in both groups (p > 0.05). Multiparous cows in group T expressed the first postpartum estrus and conceived earlier than cows in group C (p ≤ 0.05). Between days 21 to 42 postpartum, the PMN reduction rate was higher in group T animals (p ≤ 0.05). Acute phase protein levels were in general lower in group T animals, and at specific time points differed significantly from group C (p ≤ 0.05). It was concluded that the partial replacement of soybean meal by flaxseed and lupins had no negative effect on milk yield or milk composition, and improved cow fertility; which, along with the lower cost of flaxseed and lupins mixture, may increase milk production profitability.

Influence of Flaxseed (Linum usitatissimum) on Female Reproduction

This review describes the chemical composition of flaxseed (Linum usitatissimum) and its general health effects, as well as the currently available knowledge concerning its action on the female reproductive state, functions on the ovary and ovarian cells and reproductive hormones, as well as possible constituents and extra- and intracellular mediators mediating its effects on female reproductive processes. Flaxseed contains a number of biologically active molecules, which, acting through multiple signalling pathways, can determine numerous physiological, protective and therapeutic effects of flaxseed. The available publications demonstrate the action of flaxseed and its constituents on the female reproductive system - ovarian growth, follicle development, the resulting puberty and reproductive cycles, ovarian cell proliferation and apoptosis, oo- and embryogenesis, hormonal regulators of reproductive processes and their dysfunctions. These effects can be determined by flaxseed lignans, alpha-linolenic acid and their products. Their actions can be mediated by changes in general metabolism, metabolic and reproductive hormones, their binding proteins, receptors and several intracellular signalling pathways, including protein kinases, transcription factors regulating cell proliferation, apoptosis, angiogenesis and malignant transformation. Flaxseed and its active molecules are found potentially useful for improving farm animal reproductive efficiency and treatment of polycystic ovarian syndrome and ovarian cancer.

Effect of Strategic Supplementation of Dietary By-Pass Linseed Oil on Fertility and Milk Quality in Sarda Ewes

The aim of the present study was to assess whether the strategic supplementation of bypass LO can enhance reproductive indexes—fertility, lambing rate, and prolificacy—in dairy Sarda ewes at the end of lactation. To assess whether LO supplementation leads to the adsorptions of PUFAs and their subsequent utilization by the body tissues, milk composition and fatty acid content were analyzed. Forty-eight ewes were assigned to the following groups: the control group (CT; N = 24), fed with a control diet without LO; and the treatment group (LO; N = 24), fed with a diet supplemented with LO (10.8 g/ewe/day). Both diets had similar crude protein and energy levels and were offered for 38 days (−21 to +17 days after artificial insemination). The trial included an adaptation period (7 days) followed by a regular supplementation (31 days) period. Estrus synchronization was induced in all the ewes using an intravaginal sponge and equine chorionic gonadotropin. Fifty-five hours after pessaries withdrawal, all ewes were inseminated using the cervical route and fresh semen. Cholesterol (p < 0.01), high-density lipoprotein (p < 0.001), and triglyceride (p < 0.05) levels in plasma were higher in the LO group. Plasmatic levels of non-esterified fatty acids were lower in the LO group after the end of the supplementation period (p < 0.05). Milk unsaturated fatty acids (UFAs), monounsaturated fatty acids (MUFAs), total polyunsaturated fatty acids (PUFAs), PUFAs omega 3 (PUFAs-ω3) and 6 (PUFAs-ω6), and trans fatty acids were higher in the LO group (p < 0.001), while saturated fatty acids (SFAs) were higher in the CT group during the supplementation period (p < 0.001). Three days after the end of the supplementation period, the content of milk UFAs (p < 0.05), PUFAs (p < 0.001), MUFAs, and PUFAs-ω6 (p < 0.01) were still higher in the LO group. whereas SFA was higher in the CT group (p < 0.01). There was no difference between groups in terms of ovulation rate, progesterone levels in plasma, fertility rate, prolificacy, and total reproductive wastage. However, the total area of luteal tissue was higher in the LO group (p < 0.01). Results obtained demonstrated that LO supplementation exerts a positive role in corpus luteum size at the onset of the peri-implantation period in Sarda dairy ewes. Additionally, the results obtained in the present study showed that the use of dietary bypass LO affects lipid metabolites in plasma and milk fatty acid profiles, demonstrating the ALA uptake by body tissues.

Blood thyroid hormones, insulin and leptin, metabolites and enzymes in transition dairy ewes, as affected by dietary linseed and physiological stage

This study investigated the effects of dietary linseed and physiological state on blood concentrations of some metabolic hormones and indicators, in transition dairy ewes. From 21 d before lambing to 60 d post-partum, ewes were provided with one of three isoenergetic and iso‑nitrogenous pelleted concentrates, without (CTR, n = 21), or with 100 (EL-10, n = 22) or 200 g/kg (EL-20, n = 22) of extruded linseed. Animals were fed alfalfa hay ad libitum and had access to mixed pasture. Plasma thyroid hormones and insulin concentrations were not affected by diet and significantly changed by time. The last week of pregnancy T3 (2.27 ± 0.15 ng/mL) and T4 (102.63 ± 2.85 ng/mL) were lower than at 4 weeks before lambing (T3: 3.27 ± 0.27 ng/mL; T4: 125.89 ± 2.63 ng/mL). After lambing, T3 rose to be highest at 4 and 8 weeks of lactation (3.41 ± 0.22). Mean insulin peaked 2 weeks after lambing (0.31 ± 0.02 ng/mL) vs. late pregnancy (0.22 ± 0.01 ng/mL) and progressing lactation (0.18 ± 0.01 ng/mL). Plasma Leptin concentration (2.43 ± 0.03 ng/mL) was not affected by diet nor time. All the blood metabolites and enzymes investigated showed significant time x treatment interaction. Differences of several haematological parameters were found in EL vs. CTR (cholesterol, triglycerides, total protein, bilirubin, ALP, ALT), however, in most cases the values were fairly within the reference physiological ranges. Metabolic hormones are confirmed to be mainly linked to the different physiological states, energy intake and variations of energy balance, without clear effects by different sources of energy and quality of dietary lipids.

Influence of flaxseed with rumen undegradable protein level on milk yield, milk fatty acids and blood metabolites in transition ewes

An experiment was conducted to determine the effects of two levels of rumen undegradable protein (RUP) without or with whole or extruded flaxseed on milk yield, milk component, milk fatty acids (FAs) profile and plasma metabolites in transition ewes. Three weeks before and after lambing, seventy-two Baluchi ewes were used in a completely randomized design with a 3 × 2 factorial arrangement of treatments. The treatments contained 1) no flaxseed + 20% RUP (no flaxseed, low RUP [NFLR]); 2) no flaxseed + 40% RUP (no flaxseed, high RUP [NFHR]); 3) 10% whole flaxseed + 20% RUP (whole flaxseed, low RUP [WFLR]); 4) 10% whole flaxseed + 40% RUP (whole flaxseed, high RUP [WFHR]); 5) 10% extruded flaxseed + 20% RUP (extruded flaxseed, low RUP [EFLR]), and 6) 10% extruded flaxseed + 40% RUP (extruded flaxseed, high RUP [EFHR]). Ewes fed 10% extruded flaxseed exhibited higher (p < 0.001) dry matter intake (DMI) and colostrum yield (p < 0.1) compared to other treatments. Two types of flaxseed and RUP levels had no significant effect on milk yield, but milk fat and protein contents decreased and increased in diets containing 40% RUP, respectively. Ewes fed extruded flaxseed produced milk with lower concentrations of saturated fatty acids (SFA) and higher α-linolenic and linoleic acids and also polyunsaturated fatty acids (PUFA) compared to other groups (p < 0.05). During post-lambing, the ewes fed diets containing flaxseed exhibited higher concentration of serum non-esterified FAs (NEFA) compared to diets without flaxseed (p < 0.01). The concentration of serum β-hydroxybutyric acid (BHBA) decreased in the diets containing flaxseed types at pre-lambing, but increased in diets containing extruded flaxseed at post-lambing (p < 0.01). The serum glucose concentration of ewes (pre and post-lambing) which consumed diets containing extruded flaxseed or 40% RUP increased, but blood urea concentration was elevated following supplementation of diet with whole flaxseed or 40% RUP (p < 0.001). In conclusion, utilization of 10% extruded flaxseed in the diets of transition ewes had positive effects on animal performance with favorable changes in milk FAs profile. However, there is no considerable advantage to supply more than 20% RUP level in the diet of transition dairy sheep.

Effects of Flaxseed-rich Diet on Reproductive Performance in Estrous-synchronized Baluchi Ewes

The purpose of this study was to compare the effects of using different levels of flaxseed in diets on the reproductive performance of estrous-synchronized Baluchi ewes (para 3). Diets contained either basal diet (control) or different levels of extruded flaxseed (2%, 5%, 7%, 10%, and 12%) and were fed from lambing to 60 days after lambing. The ewe estrus cycles were synchronized using controlled internal drug release (CIDR) for 14 days starting from day 16 of fat supplementation. The rams were introduced 24 h after CIDR removal. The ewes fed control diets had the highest mean dry matter intake (1,800&amp;plusmn;35 g) which was declined with the increase of flaxseed levels. The experimental diets exerted no effects of urea concentration in blood plasma. However, plasma glucose concentration was lower (p &amp;lt;0.05) in the ewes fed the control diet and 2% flaxseed, compared to those in other groups. Nonetheless, there was no difference among the ewes fed 5%, 7%, 10%, and 12% flaxseed in terms of plasma glucose concentrations (p &amp;lt;0.05). The ewes fed 2% flaxseed had the highest level of plasma triglyceride concentration among other groups. In addition, the control group had the lowest level of plasma total cholesterol and low-density lipoproteins concentration in comparison to other groups (p &amp;lt;0.05). However, plasma nonesterified fatty acids and &amp;beta;-hydroxybutyrate concentrations were similar among the groups (P&amp;gt;0.05). The mean interval between CIDR removal and the exhibition of estrus ranged from 30 to 40 h with the shortest interval being recorded in the ewes fed 12% flaxseed (p &amp;lt;0.05). The control group had the lowest number of follicles on estrus day among other groups (p &amp;lt;0.05). Furthermore, the ewes fed 10% and 12% flaxseed had the highest ovulation, pregnancy, and lambing rates, compared to other groups (p &amp;lt;0.05). In conclusion, the findings revealed that feeding the ewes with 10% and 12% flaxseed resulted in the improvement of reproductive performance.

A tiered high-throughput screening approach for evaluation of estrogen and androgen receptor modulation by environmentally relevant bisphenol A substitutes

Bisphenol A (BPA) is a high production volume chemical with a broad application spectrum. As an endocrine disrupting chemical, mainly by modulation of nuclear receptors (NRs), BPA has an adverse impact on organisms and is identified as a substance of very high concern under the European REACH regulation. Various BPA substitution candidates have been developed in recent years, however, information concerning the endocrine disrupting potential of these substances is still incomplete or missing. In this study, we intended to investigate the endocrine potential of BPA substitution candidates used in environmentally relevant applications such as thermal paper or epoxy resins. Based on an extensive literature and patent search, 33 environmentally relevant BPA substitution candidates were identified. In order to evaluate the endocrine potential of the BPA replacements, a screening cascade consisting of biochemical and cell-based assays was employed to investigate substance binding to the NRs estrogen receptor α and β, as well as androgen receptor, co-activator recruitment and NR-mediated reporter gene activation. In addition, a computational docking approach for retrospective prediction of receptor binding was carried out. Our results show that some BPA substitution candidates, for which so far no or only very few data were available, possess a substantial endocrine disrupting potential (TDP, BPZ), while several substances (BPS, D-8, DD70, DMP-OH, TBSA, D4, CBDO, ISO, VITC, DPA, and DOPO) did not reveal any NR binding.

Effects of Extruded Linseed and Soybean Dietary Supplementation on Lactation Performance, First-Service Conception Rate, and Mastitis Incidence in Holstein Dairy Cows

This study quantifies the effects of extruded linseed and soybean (ELS) dietary supplementation on milk yield, composition, and fatty acid profiles, as well as first-service conception rate in Holstein dairy cows. Seventy-eight open Holstein dairy cows were divided into two groups: (1) a control, which received a basal diet; and (2) a test group, which received a basal diet supplemented with the ELS (650 g/kg of extruded linseed and 150 g/kg of extruded soybean) at a rate of 100 g/kg. In the ELS group, milk yield per day and solid not fat (SNF) yield increased by 3.26% and 0.88%, respectively, in relation to the control. Percentage milk fat decreased significantly by 1.4% in the ELS group when compared with the control. The ELS supplement resulted in a decrease in saturated fatty acids (SFAs) and an increase in monounsaturated (MUFAs) and polyunsaturated fatty acids (PUFAs) in milk. In conclusion, the supplementation of dairy cow feed with 100 g/kg of ELS increases milk yield and milk unsaturated fatty acids (especially MUFAs and PUFAs). ELS supplementation also causes a decrease in percentage fat and SFA levels but does not affect the first-service conception rate or the incidence rate of mastitis.

Interrelationships among plasma metabolites, production, and ovarian follicular function in dairy cows

Associations of blood metabolites and production variables with ovarian function and parity, specifically, interval to first ovulation (IFO) and the incidence of ovarian cysts (OC) and multiple ovulation (MOV) at the first ovulation postpartum, were determined in lactating dairy cows. This retrospective study involved data on 169 Holstein cows from three studies on the same herd. Blood samples were taken weekly from week −1 to week 4, relative to calving, and transrectal ultrasonography was performed twice weekly from day 7 to day 60 postpartum. The overall IFO was 32.6 ± 1.9 d (mean ± SEM) and did not differ among lactations. Primiparous cows were at a greater risk of failing to ovulate before day 60 postpartum and cows in the third or greater lactation were at a higher risk for OC and MOV. Blood metabolites and production variables indicating a negative energy balance were associated with cows failing to ovulate before day 35 postpartum, but were not related with OC. Increased dry matter intake and milk yield, particularly in second lactation cows, were associated with a higher incidence of OC. While beta-hydroxybutyrate acid and insulin-like growth factor 1 were associated with MOV, the relationship was weak. Reducing negative energy balance is necessary to reduce IFO but may increase the incidence of MOV.

Does feeding extruded linseed to dairy cows improve reproductive performance in dairy herds? An observational study

Feeding n-3 fatty acids (FA) is often cited as a promising strategy to tackle impaired reproduction in dairy cows. However, the scientific literature shows conflicting results that may be explained by the nature of n-3 FA used, the amount supplemented and the timing of supplementation. In addition, designing a proper experimental design to study n-3 FA and reproduction is subjected to other difficulties such as the choice of the control diet or gaining enough statistical power. The objective of this retrospective observational study was to quantify the average effects of supplementing extruded linseed (EL), a feed rich in α-linolenic acid, to dairy cows on reproductive performances under field conditions in French commercial farms. Exposure measurement to EL feeding was particularly challenging as exact cow diets are not traced in farms. Therefore, to investigate the potential dose-effect relationship, we defined a proxy of EL intake per day by using deliveries of EL based feeds from 22 companies in the study period 2008-2015 in France. An artificial insemination (AI) was considered exposed only if the cow was supplemented with EL from the calving until 17 days after AI. Based on recommendations for EL use on the field, 4 exposures classes were created: [1-50] (n = 14,126 AIs), [50-300] (n = 88,261 AIs), [300-600] (n = 66,136 AIs), and [600-1500] (n = 28,287 AIs) g/cow/d. The reference population was composed of cows that did not receive any EL between calving until 17 days after AI within herds that were supplied, but not continuously during the study period (n = 226,795 AIs). Mean daily EL intake in exposed population was 337 g/cow/d (±239.4). Reproductive performance was studied on 423,605 AIs from 1096 herds and 158,125 cows using Cox models for days to first AI and days to conception, and logistic regression models for risk of return-to-service, adjusted for factors likely to influence the reproductive performance and for a herd random effect. Risk of return-to-service between 18 and 78 days after first and second AI did not differ between exposed and reference populations, Nevertheless, the effect on the days to first AI was higher with the lowest EL intake (HR: 1.14; 95% CI: 1.11, 1.17) than with higher EL intake levels (HR ranging from 1.06 to 1.07; 95% CI: 1.04, 1.09). Similarly, for the effect on the time from calving to conception from the lowest EL intake (HR: 1.19; 95% CI: 1.15, 1.23) compared to the higher EL intake levels (HR ranging from 1.08 to 1.11; 95% CI: 1.06, 1.14). This original large-scale epidemiological study provides new insights into the effects of feeding EL at a commercially sustainable level to dairy cows.

Effect of Dietary Fish Oil on Mammary Gland Development and Milk Production of Holstein Cow

The aim of this study was to evaluate the effect of feeding oil supplement on mammary gland development and milk production responses in Holstein cows. Ten multiparous Holstein cows (42.2±9.2 d before calving, 3.25±0.25 body condition score, and 620±35 kg body weight) were randomly assigned to treatments. Treatments were a diet with oil added as palm oil (PO; n=5), or fish oil (FO; n=5) given to cows until 63 d in milk. Milk yield was recorded daily, milk composition (fat, protein, lactose, total solid and somatic cell count) was measured weekly and fatty acid profiles of milk fat were determined at first and last week of the experiment. Samples of mammary tissue were obtained at 7 and 63 d in milk by biopsy gun. Tissue slides were analyzed by Image J software. Results showed that fish oil supplemented diet compared to the palm oil supplemented diet increased milk production after 6 weeks of lactation (P<0.05), content of polyunsaturated fatty acids milk fat (P<0.05) and docosahexaenoic acid (P<0.01). Moreover, n-6:n-3 ratio was decreased by fish oil supplement (P<0.05). Histological studies showed that FO increased the relative percentage of tissue area occupied by epithelial cells as well as a number of total alveoli in each microscopic field (P<0.05). Data suggested that feeding fish oil during the dry period and early lactation could improve development and function of the mammary gland in the dairy cow.

Direct inhibitory effect of flaxseed on porcine ovarian granulosa cell functions

Flaxseed is useful as a functional food and alternative medicine owing to its beneficial health effects. Its action on ovarian cell functions and interrelationships with the upstream hormonal regulators remain unknown. Our aim was to examine the direct influence of flaxseed extract on basal porcine ovarian functions (proliferation, apoptosis), leptin release, and response to insulin-like growth factor I (IGF-I). First, we examined the effect of flaxseed extract on the accumulation of proliferation (PCNA) and apoptosis (Bax) markers and on leptin release in cultured porcine ovarian granulosa cells. Next, granulosa cells were cultured with IGF-I with and without flaxseed extract and analyzed for PCNA and Bax accumulation by quantitative immunocytochemistry and for leptin release by radioimmunoassay. Flaxseed decreased the accumulation of PCNA and increased that of Bax at all doses and reduced leptin output at 100 μg/mL. In contrast, IGF-I promoted PCNA accumulation and suppressed Bax. Flaxseed did not modify IGF-I action on these parameters. Thus, we showed that flaxseed influences porcine reproductive processes, having a direct effect on the ovary and the ability to affect ovarian cell proliferation, apoptosis, and leptin release. Furthermore, we confirmed the pro-proliferative and antiapoptotic actions of IGF-I but showed that flaxseed action on ovarian cell proliferation and apoptosis is not due to changes in the cell response to IGF-I. The potential direct anti-reproductive action of flaxseed needs to be considered during its application in nutrition, medicine, and animal production.

Effects of feeding a source of omega-3 fatty acid during the early postpartum period on the endocannabinoid system in the bovine endometrium

A total of sixteen Holstein dairy cows (35 ± 1.1 kg/d of milk yield) were randomly assigned to consider the effects of feeding omega-3 sources on endometrial endocannabinoids system (ECS) genes expression to understand the effect mechanism of omega-3 on reproductive performances during the early postpartum period to evaluate to what extent can be intervened in reproduction, e.g. via nutrition to improve fertility. Experimental diets were 1) either protected palm oil (control) or 2) extruded linseed (linseed). Cows (n = 16) were fed from calving date to 70 days in milk (DIM). There was no difference between groups (mean ± S.E.M.) in parity (3.0 ± 1.00) or body condition score (BCS) at calving day (3.1 ± 0.25). At 30 DIM, the ovulatory cycles of cows were synchronized using two injections of prostaglandin F2α (PGF2α) with a 14-day interval. On day 15 of synchronized estrous cycle (d0 = ovulation) uterine endometrial biopsies were collected to evaluate the expression of genes related to ECS (endocannabinoid receptor (CNR2), N-acyl phosphatidylethanolamine phospholipase D (NAPEPLD), fatty acid amide hydrolase (FAAH), N-acylethanolamine acid amidase (NAAA), monoglyceride lipase (MGLL)) and PGF2α. Results showed that dry matter intake and milk yield were not affected by diets. Uterine endometrial NAAA (7.69 fold), and MGLL (1.96 fold) genes expression were greater (P < 0.05) in cows fed linseed compared with control ones. The messenger RNA (mRNA) levels of CNR-2 (4.26 fold), and NAPEPLD (20.0 fold) were decreased (P < 0.05) in animals fed linseed compared to control cows. The expression of mRNA for the FAAH was not influenced by the diets. First service conception rate was greater in cows fed linseed compared to control cows (75 vs. 25%). Pregnancy loss within 32-60 day after artificial insemination (AI) was lower in cows fed linseed compared to control cows (0 vs. 100%). In conclusion these data demonstrated that positive effect of omega-3 on reproduction may act through a mechanism involving the ECS. However, more studies to be undertaken to confirm these results.

Effects of supplementation with docosahexaenoic acid on reproduction of dairy cows

The objectives were to determine the effects of supplementing docosahexaenoic acid (DHA)-rich algae on reproduction of dairy cows. Holstein cows were assigned randomly to either a control (n = 373) or the same diet supplemented daily with 100 g/cow of an algae product containing 10% DHA (algae, n = 366) from 27 to 147 days postpartum. Measurements included yields of milk and milk components, fatty acids (FA) profiles in milk fat and plasma phospholipids, resumption of ovulation by 57 days postpartum, pregnancy per artificial insemination (AI) and expression of interferon-stimulated genes in leukocytes. Feeding algae increased resumption of estrous cyclicity (77.6 vs 65.9%) and pregnancy at first AI (47.6 vs 32.8%) in primiparous cows. Algae increased pregnancy per AI in all AI in both primiparous and multiparous cows (41.6 vs 30.7%), which reduced days to pregnancy by 22 days (102 vs 124 days) compared with control cows. Pregnant cows fed algae had greater expression of RTP4 in blood leukocytes compared with those in pregnant control cows. Feeding algae increased the incorporation of DHA, eicosapentaenoic acid, conjugated linoleic acid isomers cis-9 trans-11, trans-10 cis-12 and total n-3 FA in phospholipids in plasma and milk fat. Yields of milk and true protein increased by 1.1 kg/day and 30 g/day respectively, whereas fat yield decreased 40 g/day in algae compared with that in control. Supplementing DHA-rich algae altered the FA composition of lipid fractions and improved reproduction in dairy cows. The benefits on reproduction might be mediated by enhanced embryo development based on changes in interferon-stimulated gene expression.