Pregnancy per artificial insemination in lactating dairy cows subjected to 2 different intervals from presynchronization to initiation of Ovsynch protocol
نویسندگان
چکیده
منابع مشابه
Effects of resynchronization programs on pregnancy per artificial insemination, progesterone, and pregnancy-associated glycoproteins in plasma of lactating dairy cows.
Objectives were to develop a timed artificial insemination (TAI) resynchronization program to improve pregnancy per AI and to evaluate responses of circulating progesterone and pregnancy-associated glycoproteins in lactating cows. Cows (n=1,578) were presynchronized with 2 injections of PGF2alpha, given 14 d apart starting on d 45+/-3 postpartum, followed by Ovsynch [2 injections of GnRH 7 d be...
متن کاملComparison of Pregnancy Rates after Timed Artificial Insemination in Ovsynch, Heatsynch and CIDR-Based Synchronization Protocol in Dairy Cows
The objective of this study was to compare the effects of three different estrus synchronization protocols on the pregnancy rates of lactating dairy cows. Group 1 (Ovsynch protocol; n= ) animals received 20 μg GnRH on day 0, 500 μg PGF2α on day 7 and 20 μg GnRH on day 9; Group 2 (Heatsynch protocol; n= ) received 20 μg GnRH on day 0, 500 μg PGF2α on day 7 and an injection of 1 ml estradiol cypi...
متن کاملEffect of interval from timed artificial insemination to initiation of resynchronization of ovulation on fertility of lactating dairy cows.
To compare 2 strategies for systematically resynchronizing ovulation, lactating Holstein cows (n = 763) at various days in milk and prior artificial insemination services were assigned randomly at timed AI (TAI) to receive the first GnRH injection of Ovsynch 26 (D26) or 33 (D33) d after TAI to resynchronize ovulation (Resynch) in cows failing to conceive. Cows in the D26 treatment received GnRH...
متن کاملEffects of presynchronization and length of proestrus on fertility of grazing dairy cows subjected to a 5-day timed artificial insemination protocol.
The objectives were to compare the effects of 2 methods of presynchronization and 2 lengths of proestrus on fertility of grazing dairy cows subjected to a 5-d timed artificial insemination (AI) protocol at initiation of breeding season. Lactating dairy cows (n=1,754) from 3 seasonal grazing farms were blocked within farm by breed, parity, and days in milk (DIM). Study d 0 was considered the day...
متن کاملAn investigation on the possibility of using eCG for presynchronization prior to ovsynch in dairy cow
Background: Presynchronization could enhance fertility in timed breeding programs. The best presynchronization method has to justify biological requirements and to provide practical and economic advantages. OBJECTIVES: Present study investigated the effectiveness of presynchronization with equine chorionic gonadotropin (eCG) before ovsynch (eCG-ovsynch) compared to conventional presynch-ovsynch...
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 2013
ISSN: 0022-0302
DOI: 10.3168/jds.2013-6750