INFLUENCE OF DIETARY FAT SOURCE ON REPRODUCTIVE PARAMETERS IN MARES

Abstract

Sixteen cycling mares were used to study the effects of different fat supplements (corn, soybean, and fish oil) on reproductive parameters. Mares were supplemented with oil at a rate of 342 mg/kg BW/d for two consecutive estrous cycles, with blood samples collected at each ovulation and 9 days post-ovulation. Cycle length was recorded, and serum triglycerides, non-esterified fatty acids (NEFA), progesterone, and estradiol concentrations were analyzed in serum. Fat supplementation had no effect on cycle length, serum triglycerides, progesterone, and estradiol. Decreasing NEFA concentrations throughout the study were similar to previous published literature. Cyclic changes observed in progesterone and estradiol concentrations were in accordance with expected hormone fluctuations in the estrous cycle of the mare. The results of this study indicate that the oils commonly added to feeds have no effect on the reproductive markers measured.