The use of subcutaneous progesterone-releasing devices in superovulatory treatment allow to get high results of embryo production per donor, viability and pregnancy rates after embryo transfer in cattle. Application progesterone hypodermic inserts has allowed to lower the cost price of one received embryo on 28461 rubles

Efficiency of cultivation of cow preimplantation embryos and support of pluripotent properties in different nutritive media was analyzed; a method of getting early embryos in vitro for the genetically engineered purposes was developed in the conditions of the Republic of Belarus. Oocyte separation was realized in 3; 3-6; 6-9; and 9-12 hours after ovariectomy for the studying of the influence of storage period of ovaries on the output qualitative embryos. Oocyte separation was realized by bisection with adding of 1% of fetal cattle serum, 10 units/ml of gentamicin and 1 unit/ml of heparin. Oocyte-cumulus complexes maturing took place in CO2-bath with 5% of CO2 in atmosphere of maximum humidity and temperature of 38 deg C in TS-199 (Sigma) media with entering of 25 mM/l of buffer Hepes, 10 unit/ml of gentamicin and biologically active substance (20 % of fetal calf serum, 10 mg/ml of bovine serum albumin and 5 % of estrous cow serum with 10 mg/ml of bovine serum albumin). Research result showed that application of 10 mg/ml of bovine serum albumin into TS-199 media made it possible to increase the yield of cattle embryos at the preimplantation stages in vitro conditions on 19,1%, as well as to increase the fetal calf serum in quantity 15% to the nutritive media volume up to 16,0 %. Application of sodium pyruvate and calcium lactate in the process of cultivation of early cattle embryos obtained in vitro conditions made it possible to increase the yield of preimplantation embryos on 5,4 %. Specifically, the level of transformation of morulas into blastocysts was 44,4 %

Analysis of the main indexes of embryo productivity of cow donors with a view to application of progestagenic intravaginal devices in technology of cattle embryo transplantation was realized in the conditions of the Republic of Belarus. Research results showed that application of progestogenic implants independently of the day luteal phase of sexual cycle in schemes of animal treatment made it possible to regulate the folliculogenesis of cows by mean of formation of new wave of follicles growth that could be used in increasing the efficiency of technology of transplantation of cattle embryos. Application of intravaginal devices in schemes of superovulation treatment of cows made it possible to obtain high-grade results of the main indexes of embryo production of donors in technology of cattle embryo transplantation. The technology of application of implant PRID in course of 7 and 9 days in the luteal phase of sexual cycle of donors proved to be the most optimal. It was determined that the indexes of quality composition of embryos, transplantability of fresh and frozen embryos obtained from cows induced by superovulation with application intravaginal devices corresponded to the control indexes. Application of progesterone extracting implants in the schemes of donor cows treatment schemes did not render influence on obtaining of viable animal yield after transplantation of biological material to recipients

Methods of increasing the efficiency of semen fertilizing capacity in vitro with application of hormonal and biophysical methods of influence, as well as the determination of metabolic criterion of spermium viability were studied in the conditions of the republic of Belarus. Research object was frozen-deiced sperm of cattle. Research results showed that entering of 50 mkg/ml of prostaglandin into capacitation media increased the breaking level on 2,3-3,1%, but at the same time there was the decreasing of embryo output at the pre-implantation stages. Increasing of estrophan concentration in media for capacitation up to 100 mkg/ml, and its addition into media for fertilization made it possible to increase the embryo output at the stage of morula-blastocyte up to 1,6-18,5%. Application of 8mg/ml of caffeine as a capacitation agent for the preparation of cattle sperm for fertilization in vitro made it possible to obtain embryo output of 16,7% with breaking level of 25,9%. Influence of directed polarized light on semen after its maturation was more efficient in comparison with the influence on it just after swim-up procedure; the output of pre-implantation embryos was 16,7% against 12,9%. Application of laser radiation made it possible to get 14,7 % of morula-blastocytes. Intensity of sperm breath (0,41-0,63 tg), intensity of lipid peroxidation (0,88-0,97 conditional units /10E6 cells), intracellular content of adenosine triphosphate (0,97-1,60 Nm/10E6 cells) and membrane potential (33-35 uV) in the conditions of matured in vitro oocyte made it possible to get 16,4-17,3% of pre-implantation embryos with the breaking level of 39,8-42,3%

The problem of creation of improved conditions for cattle oocyte maturation in vitro was studied in the Republic of Belarus. The objects of study were cattle oocytes and embryos of early preimplantation stages of development obtained in vitro conditions. Research results showed that application of bovine serum in complex with embryonic or fetal serum in the process of oocyte cultivation in vitro conditions made it possible to obtain 35,5-44,8% of breaking down cells and 16,1-17,2 % of embryos at the stage of morula-blastocyte. Entering of 0,02 ng/ml of gonadotropin-releasing hormone (Surfagon) into media for oocyte maturation at the cost of regulation of the processes of growing and development of oocyte-cumulus complexes made it possible to increase of yield of matured till the stage of metaphase II oocytes up to 89,3 %. At the same time, the yield of divided embryos after fertilization increased on 2,5 % in comparison with control indexes and amounted 45,2 %. Research results showed that the synthetic phytohormone epibrassinolide could be used as a biologically active factor in the process of getting early embryos in vitro in concentration of 2 x 10E-7 – 2 x 10E-9 mole/l. It made it possible to get 46,4-55,0 % of divided cells and 14,2-16,2% preimplantation embryos