Ovarian dynamics and milk progesterone concentrations in cycling and non-cycling buffalo-cows (Bubalus bubalis) during Ovsynch program.
The objective was to evaluate ovarian dynamics and progesterone concentrations in cyclic (CYC, n=10) and non-cyclic (NCY, n=8) buffalo-cows during Ovsynch program. All cows received GnRH on day 0, PGF2alpha on day 7, and GnRH on day 9, and AI 14 h later. Ovarian structures were monitored by ultrasound and milk samples were collected for progesterone (P4) analysis. The first GnRH resulted in ovulation in CYC (90%) and NCY (62.5%) cows. By day 7, almost all cows had large follicle and lutein tissue. Luteolytic responses to PGF2alpha were 80 and 87.5% for CYC and NCY cows, respectively. Following second GnRH, ovulation occurred in 80% of CYC and 100% of NCY cows. Ovulation began earlier (12 h following second GnRH) and extended for longer (36 h) in NCY cows, when compared to CYC cows (36 and 12 h, respectively). The mean P4 levels increased from days 0 through 7 in CYC and NCY cows and levels were higher in CYC group. Conception rates were 60 and 37.5% in CYC and NYC cows, respectively. Early and asynchronous ovulation and luteal sub-function seemed to be a problem in NCY cows. Inseminating NCY cows twice, at 0 and 24 h of the second GnRH is recommended.
Ali
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A
Department of Theriogenology, Faculty of Veterinary Medicine, Assiut University, Assiut 71526, Egypt. ahmedali77@hotmail.com
Fahmy
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S
D000818:Animals; D002020:Buffaloes / Q000378:metabolism / Q000502:physiology*; D015237:Dinoprost / Q000494:pharmacology; D004971:Estrus / Q000187:drug effects / Q000378:metabolism*; D004973:Estrus Synchronization / Q000187:drug effects; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D007315:Insemination, Artificial / Q000662:veterinary; D008892:Milk / Q000378:metabolism*; D010053:Ovary / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism*; D010060:Ovulation / Q000502:physiology; D011247:Pregnancy; D018873:Pregnancy Rate; D011374:Progesterone / Q000378:metabolism*; D014463:Ultrasonography
D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D015237:Dinoprost