Evaluation of the Effects of GnRH and hCG Administrations during and after Insemination on Fertility Parameters of Dairy Cows

Background: Getting pregnant and maintenance of the pregnancy in cows is crucial for dairy farmers sustainable production. Many methods are used this purpose, one them administration gonadotropins at insemination later early embryonic period. In study, it was aimed to investigate effects different gonadotropin applications on fertility. Methods: A total 406 were divided randomly into five treatment groups according GnRH (10 µg buserelin acetate, im) hCG (1500 IU, administrations time periods AI post as; GI (n=84, d7; hCG), GII (n=106, GnRH), GIII (n=62, d0 GIV (n=80, GV (n=74, placebo: 2.5 ml 0.9% NaCl). Pregnancy control done day 30 45 AI. Fertility parameters (conception rate, first service per AI, loss) calculated with obtained data. Result: Our findings indicated that double dose caused an improvement fertility greater than 150 DIM. Also, conception rates higher parity, milk yield lower BCS improved d7. We concluded double-dose d7 can be improve after DIM parity yield.