Name: Influence of Supplemental Fats on Reproductive Tissues and Performance of Lactating Cows
aDepartment of Animal Science, Faculty of Animal Science and Food Technology, Agricultural Sciences and Natural Resources University of Khuzestan, P.O. Box 63517-73637, Mollasani, Ahvaz, Iran, bDepartment of Animal Science, Campus of Agriculture and Natural Resources, University of Tehran, Karaj, Iran, c Department of Animal Science and Industry, Kansas State University, Manhattan, 66502, United States
Abstract: Fat supplementation (about 3% of dietary dry matter) has often positively influenced the reproductive status of the dairy cow, including increased size of the ovulatory follicle, increased numbers of ovarian follicles, increased plasma concentration of progesterone, reduced secretion of prostaglandin metabolite, increased lifespan of the corpus luteum, and improved fertility. Supplemental fat may allay partially negative energy status during the early postpartum period, yet often the positive reproductive influence of supplemental fat has been independent of the energy status of the cow. The fatty acid profile of supplemental fats is influential to their impact. Linoleic acid and eicosapentaenoic acid (found in fish meal) are proven inhibitors of cyclooxygenase in endometrial tissue of dairy cows. As a result, endometrial secretion of PGFα can be suppressed, thus potentially preventing early embryonic death. This process may be aided by the effect fat has in suppressing estradiol- 17β secretion, thus reducing uterine PGF۲α secretion and decreasing the sensitivity of the corpus luteum to PGF۲α. Targeting of dietary fatty acids toward ovarian and uterine function may enhance efficiency of reproductive management and fertility.
Key Words: fat, progesterone, prostaglandin, reproduction