Effects of resynchronization strategies for lactating Holstein cows on pattern of reinsemination, fertility, and economic outcome

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• 作者：Luí ; s G.D. Mendonç ; a^a ; ^b ; Steven T. Dewey^c ; Glá ; ucio Lopes Jr.^b ; Fernando A. Rivera^b ; Fá ; bio S. Guagnini^b ; John P. Fetrow^a ; Todd R. Bilby^c ; ^d ; Ricardo C. Chebel^a ; ^b ; ^{chebe002@umn.edu}
• 关键词：Lactating dairy cow ; Resynchronization ; Re-insemination pattern
• 刊名：Theriogenology
• 出版年：2012
• 期刊代码：98_0093691x
• 类别：abs
• 出版时间：1 April, 2012
• 卷：77
• 期：6
• 页码：1151-1158
• 文件大小：639 K

摘要

The objectives were to evaluate the pattern of re-insemination, pregnancy outcomes to re-insemination in estrus and at fixed time, and economic outcomes of lactating Holstein cows submitted to three resynchronization protocols. Cows were enrolled in the Experiment at 32 卤 3 d after pre-enrollment Artificial Insemination (AI), 7 d before pregnancy diagnosis, and randomly assigned to three resynchronization protocols. All cows diagnosed not pregnant at 39 卤 3 d after pre-enrollment AI were submitted to the Cosynch72 (Day 0 GnRH, Day 7 prostaglandin F_2伪, and Day 10 GnRH and fixed time AI). Cows assigned to the control treatment received no further treatment, cows assigned to the GGPG treatment received a GnRH injection on Day 鈭?, and cows assigned to the CIDR treatment received a controlled internal drug release (CIDR) insert containing 1.38 g of progesterone from Days 0-7. Cows observed in estrus were re-inseminated on the same day. Pregnancy was diagnosed at 39 卤 3 and 67 卤 3 d after re-insemination. Costs of the resynchronization protocols were calculated for individual cows enrolled in the study and pregnancies generated were given a value of $275. The GGPG treatment resulted in the slowest (P 鈮?0.06) rate of re-insemination. Overall pregnancy per AI (P/AI) at 39 卤 3 (P = 0.50) and 67 卤 3 (P = 0.49) d after re-insemination were not affected by treatment. Although cost of the control protocol was (P < 0.01) the smallest, return per cow resynchronized was (P < 0.01) greater for GGPG and CIDR protocols. We concluded that presynchronizing the estrous cycle of cows with GnRH or treating cows with a CIDR insert during resynchronization altered the pattern of re-insemination and improved the economic return of resynchronized cows.