Authors: NUMAN AKYOL, SEDAT HAMDİ KIZIL, MUHARREM SATILMIŞ, TAHİR KARAŞAHİN, SERKAN ERAT
Abstract: The aim of this study was to determine the possibility of yielding more transferable embryos from cows superovulated with/without exogenous progesterone (ear implant and intravaginal device). Two experiments were conducted in Holstein Friesian cows to evaluate the effect of exogenous progesterone on the yield of corpus luteum (CL), total embryo and ova, and transferable embryos before superovulation. A superovulation program using 2 different progesterone resources was applied (G1 = intravaginal device, G2 = ear implant). Superovulation and uterus irrigations were done at 28-day intervals in the treatment groups. Cows in the control group were superovulated at 60-day intervals without application of exogenous progesterone. The mean numbers of CLs and transferable embryos for the G1, G2, and control groups were, respectively 4.82 ± 0.29, 6.71 ± 0.29, and 7.81 ± 0.31 for CLs and 0.86 ± 0.35, 3.50 ± 0.35, and 1.53 ± 0.39 for transferable embryos. It was shown that exogenous manipulation of the estrus cycle by progesterone could be applied without superovulation intervals in Holstein cows. It may also be postulated that the ear implant was more effective than the intravaginal device as a progesterone source in the superovulation program.
Keywords: Cattle, exogenous progesterone, consecutive superovulation
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