Presynchronization with Double-Ovsynch improves fertility at first postpartum artificial insemination in lactating dairy cows
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Date
2012-12
Authors
Herlihy, Mary M.
Giordano, Julio O.
Souza, Alex H.
Ayres, Henderson
Ferreira, Roberta M.
Nascimento, Anibal B.
Guenther, Jerry N.
Gaska, Jerry M.
Kacuba, S. J.
Crowe, Mark A.
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier Science
Abstract
The objective of this study was to compare circulating progesterone (P4) profiles and pregnancies per AT (P/AI) in lactating dairy cows bred by timed artificial insemination (TAT) following Ovsynch-56 after 2 different presynchronization protocols: Double-Ovsynch (DO) or Presynch-Ovsynch (PS). Our main hypothesis was that DO would increase fertility in primiparous cows, but not in multiparous cows. Within each herd (n = 3), lactating dairy cows (n = 1,687; 778 primiparous, 909 multiparous) were randomly assigned to DO [n = 837; GnRH-7d-PGF(2 alpha)-3d-GnRH-7d-Ovsynch-56 (GnRH-7d-PGF(2 alpha)-56h-GnRH-16hTAI)] or PS (n = 850; PGF(2 alpha)-14d-PGF(2 alpha)-12d-Ovsynch-56). In 1 herd, concentrations of P4 were determined at the first GnRH (GnRH1) of Ovsynch-56 and at d 11 after TAI (n = 739). In all herds, pregnancy was diagnosed by palpation per rectum at 39 d. In 1 herd, the incidence of late embryo loss was determined at 74 d, and data were available on P/AI at the subsequent second service. Presynchronization with DO reduced the percentage of animals with low P4 concentrations (<0.50 ng/mL) at GnRH1 of Ovsynch-56 (5.4 VS. 25.3%, DO vs. PS). A lesser percentage of both primiparous and multiparous cows treated with DO had low P4 concentrations at GnRH1 of Ovsynch-56 (3.3 vs. 19.7%, DO vs. PS primiparous; and 8.8 vs. 31.9%, DO vs. PS multiparous). Presynchronization with DO improved P/AI at the first postpartum service (46.3 vs. 38.2%, DO vs. PS). Statistically, a fertility improvement could be detected for primiparous cows treated with DO (52.5 vs. 42.3%, DO vs. PS, primiparous), but only a tendency could be detected in multiparous cows (40.3 vs. 34.3%, DO vs. PS, multiparous), consistent with our original hypothesis. Presynchronization treatment had no effect on the incidence of late embryo loss after first service (8.5 vs. 5.5%, DO vs. PS). A lower body condition score increased the percentage of cows with low P4 at GnRH1 of Ovsynch-56 and reduced fertility to the TAI. In addition, P4 concentration at d 11 after TAI was reduced by DO. The method of presynchronization at first service had no effect on P/AI at the subsequent second service (34.7 vs. 36.5%, DO vs. PS). Thus; presynchronization with DO induced cyclicity in most anovular cows and improved fertility compared with PS, suggesting that DO could be a useful reproductive management protocol for synchronizing first service in commercial dairy herds.
Description
Keywords
Agriculture, Food science & technology, Presynchronization, Ovsynch, Dairy cow, Pregnancy rate, Body condition, Reproductive-performance, Ovulatory follicle, Hormone injection, Pregnancy rates, Milk-production, Risk-factors, Synchronization, Animalia, Bos
Citation
Herlihy, M. M. vd. (2012). "Presynchronization with Double-Ovsynch improves fertility at first postpartum artificial insemination in lactating dairy cows". Journal of Dairy Science, 95(12), 7003-7014.