Synchronization of hunting and embryo survival in cows of the black-and-white breed at the hormonal induction of superovulation

The authors investigated the efficiency of the use of hormonal preparations for hunting synchronization in cows and heifers of the Black-and-White breed. The influence of different factors on the fertilization during inducible hunting and superovulation and also on the embryo survival after transplantation was estimated. It was shown, that gonadotropins in combination with prostaglandin need to be applied for synchronization of sexual cycle in donors and recipients. The use of synthetic gonadoliberin corrects the possible disturbances in ovulation, that permit to obtain the embryos from high productive cows in more early period after calving. At that the variation of ovulation number, fertility of ovule, number and stage of development of embryos ready for transplantation in superovulated cows-donors depend on duration of hunting period. The optimal concentrations of progesterone and estradiol in cow's blood under the apply of prostaglandins are 3,1 ng/ml and 28,9 pg/ml, respectively. The possibility of ovary stimulation for accelerated completion of post-natal period and recovery of reproductive function of cows-donors of embryos is considered.