Effect of presynchronization with human chorionic gonadotropin or gonadotropin-releasing hormone 7 days before resynchronization of ovulation on fertility in lactating dairy cows
نویسندگان
چکیده
منابع مشابه
Effect of presynchronization with human chorionic gonadotropin or gonadotropin-releasing hormone 7 days before resynchronization of ovulation on fertility in lactating dairy cows.
Our objectives were to (1) compare the effect on pregnancies per artificial insemination (P/AI) of presynchronization of the estrous cycle with human chorionic gonadotropin (hCG) 7d before resynchronization of ovulation (Resynch) initiated 25 d after timed artificial insemination (TAI) and compare the presynchronization treatment with the Double-Ovsynch (DO) protocol, and (2) evaluate whether h...
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One strategy for improving fertility in cattle is mid-cycle administration of GnRH to increase progesterone secretion and delay luteolysis. This strategy might be especially useful during hot weather because heat stress increases uterine prostaglandin release and reduces development of the elongating embryo. A series of experiments was conducted to test the efficacy of GnRH for increasing ferti...
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AIM Bovine ovarian cysts are a common cause of economic loss in modern dairy herds. The objective of the present study was to evaluate the reproductive responses to three protocols using hCG, GnRH and cloprostenol when the definite diagnosis of the type of ovarian cyst is/is not possible in dairy cows. MATERIALS AND METHODS A total of 144 lactating dairy cows with ovarian cysts were divided i...
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The objective was to evaluate the effect of equine chorionic gonadotropin (eCG) and hCG post artificial insemination (AI) on fertility of lactating dairy cows. In Experiment 1, cows were either treated with eCG on Day 22 post AI (400 IU; n = 80) or left untreated (n = 84). On Day 29, pregnant cows were either treated with hCG (2500 IU; n = 32) or left untreated (n = 36). Pregnancy and progester...
متن کاملThe effect of administration of gonadotropin releasing hormone analogue at estrus or during luteal phase on reproductive performance of dairy cows maintained under sub-temperate climate
Overall, 531 dairy cows were inseminated with the aim to study their reproductive performance following administration of GnRH analogue on different days of estrous cycle with different doses. These cows were divided into six treatment and one control group. Depending upon different treatment groups, Buserelin acetate was injected at a dose of 10.5 µg or 21.0 µg on different days (0, 5 or 12) o...
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 2012
ISSN: 0022-0302
DOI: 10.3168/jds.2011-5035