Calf removal improves conception rates to the Ovsynch and CO-Synch protocols1
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چکیده
Beef cows (n = 473) from two locations were stratified by breed, postpartum interval, age, and AI sire and were randomly allotted to one of four treatments for synchronization of ovulation. Ovulation synchronization protocols included the Ovsynch protocol with (n = 114) or without (n = 123) 48-h calf removal from d 7 to 9 (d 0 = 1st GnRH injection) or the COSynch protocol with (n = 119) or without (n = 117) 48h calf removal from d 7 to 9. The Ovsynch protocol included administration of GnRH (100 g; i.m.) on d 0, PGF2α (25 mg; i.m.) on d 7, GnRH (100 g; i.m.) on d 9, and timed insemination on d 10. The CO-Synch protocol included administration of GnRH (100 g; i.m.) on d 0, PGF2α (25 mg; i.m.) on d 7, and GnRH (100 g; i.m.) with timed insemination on d 9. Blood samples were collected from all cows on d −10 and d 0 for analysis of serum progesterone. Cows with at least one serum progesterone concentration greater than 1 ng/mL were
منابع مشابه
Calf removal improves conception rates to the Ovsynch and CO-Synch protocols.
Beef cows (n = 473) from two locations were stratified by breed, postpartum interval, age, and AI sire and were randomly allotted to one of four treatments for synchronization of ovulation. Ovulation synchronization protocols included the Ovsynch protocol with (n = 114) or without (n = 123) 48-h calf removal from d 7 to 9 (d 0 = 1st GnRH injection) or the CO-Synch protocol with (n = 119) or wit...
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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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