EFFECTS OF SUPPLEMENTING MARE DIETS WITH MARINE-DERIVED N-3 FATTY ACIDS ON SERUM, FOLLICULAR FLUID AND FOLLICULAR DYNAMICS DURING THE ESTROUS CYCLE

The objective of this study was to evaluate the reproductive effects of supplementing normally cycling mares with marine-derived omega-3 (n-3) fatty acids during the estrous cycle. Fifteen mares were assigned to a control diet (CONT, n=7) or a fish oil supplemented diet (FO, n=8) containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The FO mares received 18.48 g EPA/10.08 g DHA/mare/d. At the start of the trial, mares were synchronized using a progesterone and estradiol protocol. Following synchronization, mares were monitored with transrectal ultrasonography throughout the second estrous cycle. Ovarian activity, ovulation, and presence of a corpus luteum were noted. Mares were ultrasounded throughout the third estrous cycle until a 35 mm follicle was detected. Upon detection of the 35 mm follicle, hCG was administered. Within 16 hr, transvaginal ultrasound-guided follicular aspiration (TUGA) was performed on the preovulatory follicle, signifying the end of the trial. Follicular fluid was analyzed for fatty acid and hormone concentrations. Serum fatty acids were measured every 2 wk and serum hormone concentrations were analyzed during the second estrous cycle at 5 d to 1 d prior to ovulation, at ovulation, and 3 and 5 d post-ovulation. Samples were als