Failure of timed inseminations and associated luteal function in dairy cattle after two injections of prostaglandin F2-alpha

摘要: Abstract Lactating Holstein cows (n = 235) were used to study changes in luteal function after two injections of prostaglandin F 2 -alpha (PGF -alpha) administered induce estrus for timing the first postpartum inseminations. Cows assigned randomly at parturition experimental groups and one control group. Control 59) inseminated a spontaneous beginning 40 d postpartum. The remaining given PGF 11 apart, 46 After second injection (0 h), 1) once 80 h 119) or 2) twice 72 96 57). Progesterone was measured blood serum collected from all 0 48 each throughout anticipated phase following injection. Conception rates (23%) (30%) lower (P detected estrus, conception rate twice-inseminated (55%) similar that controls, whereas once-inseminated (38%) tended be 0.09). Lower timed inseminations resulted failure luteolysis (13% cows) presence low ( -alpha. These results suggest lowered because poor insemination relative estrual events, less than expected induced luteolysis, lack time latter appeared result both prolonged anestrus ovulatory previous