Dietary supplementation of n-3 polyunsaturated fatty acid alters endometrial expression of genes involved in prostaglandin biosynthetic pathway in breeding sows (Sus scrofa).

The present investigation was designed to study the effect of dietary supplementation of omega-3 (n-3) PUFA on endometrial expression of fertility-related genes in breeding sows. Sixteen crossbred sows were randomized to receive diets containing 4% (wt/wt) flaxseed oil as n-3 PUFA source (TRT group) or iso-nitrogenous, iso-caloric standard control diet (CON group), starting from the first day of estrus up to 40 days and were artificially bred on the second estrus. Endometrial samples were collected during days 10-11 and 15-16 post-mating for studying relative expression profile of candidate genes viz. Prostaglandin F Synthase (PGFS), microsomal Prostaglandin E Synthase-1 (mPGES-1) and Carbonyl Reductase-1 (CBR-1) using quantitative Real-Time PCR. Expression level of mPGES-1 gene transcript was 2.1-fold higher (P < 0.05) during 10-11 days of pregnancy and 1.4-fold higher (P > 0.05) during 15-16 days of pregnancy in TRT group as compared to CON group. Relative expression of PGFS gene transcript was significantly lower (P < 0.05) during 10-11 days of pregnancy in TRT group while there was no significant effect (P > 0.05) of dietary supplementation during 15-16 days of pregnancy. Endometrial mRNA level of CBR1 was significantly lower (P < 0.05) with 3.93-fold decrease in TRT group during 10-11 days of pregnancy whereas 2.82-fold reduction in expression (P > 0.05) was observed subsequently during 15-16 days of pregnancy as compared to CON group. Collectively, these results indicate that dietary n-3 PUFA supplementation can modulate gene expression of key enzymes in prostaglandin biosynthetic pathway during early gestation, which in turn might have beneficial impact on overall reproductive response in breeding sows. These findings partly support strategic dietary supplementation of plant-based source of n-3 PUFA with an aim to improve overall reproductive performance in sows.

Resumption of ovarian cyclicity and fertility response in bull-exposed postpartum buffaloes.

A study was undertaken to evaluate the effect of bull exposure on resumption of ovarian cyclicity and fertility response in postpartum buffaloes raised under standard farm conditions. A total of 24 Murrah buffaloes was randomly grouped to receive one of the following treatments: (1) exposure to a vasectomised bull from 40th to 90th day postpartum (bull-exposed, BE, n=11) and (2) isolated from bull (non-exposed, NE, n=13). Changes in the progesterone concentration were used to assess the resumption of ovarian cyclicity. Postpartum interval to resumption of ovarian cyclicity (47+/-2.58 days vs. 56+/-2.37 days, p<0.05) as well as behavioral estrus (57+/-3.61 days vs. 71+/-5.13 days, p<0.05) was shorter in bull-exposed animals than control animals. Similarly, animals in the BE group had significantly shorter interval to postpartum ovulation (48+/-2.69 days vs. 57+/-2.37 days, p<0.05). Reduced incidence of silent ovulation was observed in BE group compared to NE group (18.18% vs. 50%). More than half proportion of animals in BE group conceived by 60 days postpartum compared to a very low proportion of animals in NE group (54% vs. 15%, p<0.05). Furthermore, first service conception rate in BE animals was significantly greater than NE animals (100% vs. 37.50%, p<0.05). In conclusion, continuous bull exposure to buffaloes during later postpartum period accelerates resumption of ovarian cyclicity, reduces incidence of silent ovulation and enhances first service conception rate. These results indicate that introduction of bulls to buffalo herd could be a rational management strategy for reducing the postpartum anestrus by enhancing reproductive function in buffaloes.