Roelofs J B, Bouwman E B, Pedersen H G, Rasmussen Z Riestra, Soede N M, Thomsen P D, Kemp B
Adaptation Physiology, Department of Animal Science, Wageningen University, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
Anim Reprod Sci. 2006 Jul;93(3-4):366-71. doi: 10.1016/j.anireprosci.2005.09.004. Epub 2005 Oct 26.
The objective of the present study was to examine whether different intervals between insemination and ovulation have an influence on the sex of seven-day-old embryos in dairy cattle. Cows were inseminated once with semen of one of two bulls of proven fertility between 36 h before ovulation and 12 h after ovulation. Time of ovulation was assessed by ultrasound at 4-h intervals. In total, 64 embryos were determined to be male or female. Of these 64 embryos, 51.6% were female. The sex ratio in the various insemination-ovulation intervals (early: between 36 and 20 h before ovulation; intermediate: between 20 and 8 h before ovulation; late: between 8 h before and 12 h after ovulation) did not significantly differ from the expected 1:1 sex ratio (50, 50 and 55% females, respectively). Bull (Bull A and B) and Parity (primiparous and multiparous) had no influence on the expected 1:1 sex ratio either. The number of cell cycles was similar for male and female (P = 0.23) embryos when quality of the embryo (P < 0.0001) was included in the model. The results of this study indicate that, in cattle, the interval between insemination and ovulation does not influence the sex ratio of seven-day-old embryos.
本研究的目的是检验授精与排卵之间的不同间隔时间是否会对奶牛7日龄胚胎的性别产生影响。在排卵前36小时至排卵后12小时之间，用两头生育力已得到证实的公牛之一的精液对奶牛进行一次授精。每隔4小时通过超声评估排卵时间。总共确定了64个胚胎的性别。在这64个胚胎中，51.6%为雌性。在不同的授精-排卵间隔（早期：排卵前36至20小时；中期：排卵前20至8小时；晚期：排卵前8小时至排卵后12小时）中，性别比例与预期的1:1性别比例（分别为50%、50%和55%为雌性）没有显著差异。公牛（公牛A和B）和胎次（初产和经产）对预期的1:1性别比例也没有影响。当将胚胎质量（P<0.0001）纳入模型时，雄性和雌性胚胎的细胞周期数相似（P=0.23）。本研究结果表明，在奶牛中，授精与排卵之间的间隔时间不会影响7日龄胚胎的性别比例。
