Effect of different levels of n-3 polyunsaturated fatty acids rich fish oil supplementation on the ovarian and endometrial functions in the goat (Capra hircus).

Decreasing the ratio of n-6 to n-3 polyunsaturated fatty acid (PUFA) through dietary manipulation improves the reproductive functions in the dairy cow. This study was conducted to determine the effect of dietary supplementation of n-3 PUFA rich fish oil that provided different levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) to determine the optimum dose with respect to endometrial and ovarian functions in the doe. Normal cyclic goats (n = 20) were divided into four groups (n = 5/group) and the fish oil was supplemented for 55 days such that EPA and DHA content were 0, 72, 156 and 312 mg/Kg body weight for CON, LOW, MED and HIGH groups, respectively. The diet was made isonitrogenous and isocaloric. Estrus was synchronized by two PG regimen at 11 days apart with first PG on day 25 of supplementation. Experimental does were observed from second PG till day 17 post-estrus. Ovarian ultrasound revealed that the follicular attributes were comparable among the groups; however, the diameter of CL on day 5 post-estrus was significantly larger in the MED group. Fish oil supplementation even at the lowest dose significantly decreased the serum estradiol (E2) and basal as well as oxytocin (OXT) induced PGFM during the late luteal phase of the estrous cycle (P < 0.05). Further, the MED group showed a significant decrease in the serum E2 on day 17 post-estrus as compared to LOW group. A significant increase in the progesterone (P4) on day 14 post-estrus was recorded in the MED group. Neither the effect of treatment nor time was significant either on day 16 or 17 post-estrus with respect to PGEM following OXT challenge (P > 0.05). It is concluded that the dietary fish oil inhibited OXT induced PGF2α release and decreased E2 during the late luteal phase of the estrous cycle in the doe, which will have a favourable effect on the maternal recognition of pregnancy. In addition, MED level (156 mg/Kg body weight) increased the CL size and circulating P4 during the luteal phase.

Effect of dietary supplementation of omega-3 polyunsaturated fatty acid (PUFA) rich fish oil on reproductive performance of the goat (Capra hircus).

Dietary supplementation of n-3 PUFA decreases the luteolytic PGF2α and improves the pregnancy rate in the dairy cow. However, its effect in the goat is not known. Accordingly, we studied the effect of supplementation of n-3 PUFA rich Fish oil (FO) on different reproductive events in the goat. Cycling goats (n = 30) were divided into two equal groups and fed an isocaloric and isonitrogenous diet supplemented with either FO (TRT; n = 15) or palm oil (PO) (CON; n = 15) @ 0.6 mL/kg body weight for 72 days during the breeding season. Estrus synchronization was done on day 25 and 36 of supplementation using two PG regimen and the goats in estrus were bred. Mean interval from PGF2α administration to the onset of estrus was 12 h longer (P < 0.05) in the TRT group than that of CON. The number of preovulatory follicles (POF) and ovulation rate was significantly higher in FO supplemented goats (P < 0.05) by 39.64 and 41.35%, respectively. Though the corpus luteum diameter was significantly higher (P < 0.05) on day 5, 8 and 11 post-breeding in the TRT group, mean serum progesterone (P4) did not differ significantly (P > 0.05). Mean concentration of serum estradiol (E2) was significantly (P < 0.01) lower in the FO supplemented group during day 0-60 post-breeding which could be due to significantly low serum cholesterol (P < 0.01). Though the serum concentration of PGF2α metabolite (PGFM) and PGE2 metabolite (PGEM) in the pregnant goats was significantly (P < 0.05) lower in the TRT group on day 16 and 17 post-breeding, the ratio of PGEM to PGFM remained unaffected suggesting a favourable effect of FO supplementation on the early pregnancy. The number of embryos, twinning rate and kidding rate were high in FO supplemented group though it was non-significant. However, gestation length, birth weight of kids and neonatal behaviour were comparable between the groups (P > 0.05). In conclusion, supplementation of n-3 PUFA rich FO significantly increased the number of POF and ovulation rate with numerical increase in the kidding rate. Further, it decreased the serum E2 and PGFM during the critical window of pregnancy recognition in the doe.