Effects of cloprostenol sodium at final prostaglandin F2α of Ovsynch on complete luteolysis and pregnancy per artificial insemination in lactating dairy cows.

摘要: Luteolysis is a key event in Ovsynch programs of lactating dairy cows. Studies indicate that as many 20% cows treated with Presynch/Ovsynch program have delayed or incomplete luteolysis using dinoprost tromethamine. Cows must complete to chance become pregnant. Dinoprost tromethamine has short half-life approximately 7 8min. Cloprostenol sodium more resistant endogenous metabolism and maintained circulation for longer time (half-life=3h). The objective was determine if cloprostenol could increase the percentage subsequent pregnancy per artificial insemination (P/AI) compared when administered within presynchronization plus first (n=652) an resynchronization second later AI (second+; n=394). Blood samples were collected daily 5 d beginning at PGF(2α) subset (n=680) second+ measure circulating concentrations progesterone (P(4)) estradiol (E(2)). Complete defined functional corpus luteum (CL) treatment serum P(4) <0.5 ng/mL 56, 72, 96 h after treatment. Percentage CL had not greater (79 vs. 80%, respectively) (70 72%, respectively). In addition, mean less following Pregnancy tended be than (40 35%; but (23 21%, probability undergoing 39 timed (i.e., 50% pregnant 8 28% 4 P(4)). Serum E(2) 56 positive predictor AI. summary, improve P/AI. pregnancy.