Pregnancy outcomes in two commercial dairy herds following hormonal scheduling programs
1999
Keister, Z.O. | DeNise, S.K. | Armstrong, D.V. | Ax, R.L. | Brown, M.D.
There are a number of options for hormonal management of post partum dairy cows; however, only a few studies have made direct comparisons of these programs in commercial herd settings. We compared reproductive management programs of 2 commercial dairy herds to evaluate the efficacy of prostaglandin-based treatment regimens on reproductive outcomes. Cows in Herd A were left untreated and served as the negative controls. Cows in Herd B were given PGF(2alpha) every 14 d until first insemination beginning 45 d postpartum and served as the positive controls. Treatment 1 (Ovsynch), initiated randomly during the estrous cycle, consisted of sequential injections of GnRH, PGF(2alpha), GnRH again and insemination 16 to 20 h later. Treatment 2 consisted of an Ovsynch protocol, as described above, which was begun 7 d post estrus (Ovsynch + 7). In Herd A, the number of days from parturition to conception (days open) for controls, for Ovsynch and for Ovsynch + 7 were 126, 112 and 102, respectively. In Herd B, respective days open were 102, 100 and 93 for controls, Ovsynch and Ovsynch + 7. Hormonal intervention reduced the number of days open in both herd.
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