Pregnancy outcomes in two commercial dairy herds following hormonal scheduling programs.
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 PGF2alpha every 14 d until first insemination beginning 45 d post partum and served as the positive controls. Treatment 1 (Ovsynch), initiated randomly during the estrous cycle, consisted of sequential injections of GnRH, PGF2alpha, 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 herds.
Keister
Z O
ZO
Department of Animal Sciences, University of Arizona, Tucson, USA.
DeNise
S K
SK
Armstrong
D V
DV
Ax
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RL
Brown
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MD
D000818:Animals; D002417:Cattle / Q000502:physiology*; D003612:Dairying; D015237:Dinoprost / Q000008:administration & dosage*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage*; D007315:Insemination, Artificial / Q000662:veterinary; D007774:Lactation; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000662:veterinary*
D007987:Gonadotropin-Releasing Hormone; D015237:Dinoprost