Morphological characteristics of the oocyte–cumulus complexes bos taurus and bos indicus of different purpose productivity

Abstract

In the technology of in vitro embryo production in bovines, qualitative and quantitative indicators of the initial population of viable oocytes determine the successful output of blastocysts suitable for native embryotransfer or vitrification Therefore the study of reproductive potential of cows Bos taurus and Bos indicus (zebu cattle) of different directions of productivity by the method of assessing the quality and quantity of oocytes is of scientific and practical interest. The aim of this study was to conduct a comparative analysis of Russian and Brazilian cattle on the yield of oocyte–cumulus complexes (OCC) and their morphological characteristics in the populations of dairy and beef cattle productivity. The following samples of cows were formed: Aberdeen–Angus breed n=82 (Russian Federation); black–and–white breed n=62 (Russian Federation); Nelore n=149 (Brazil); Gir n=63 (Brazil). The material of the study was oocyte–сumulus complexes obtained in the result of transvaginal puncture of follicles (transvaginal aspiration of oocytes TAO, ovum pick–up OPU). The quality of OCC was assessed by the following morphological parameters: the presence of cumulus layer and its quality, oocytes size, homogeneity and color of ooplasm, turgor. The number of viable OCC from the total amount is: Aberdeen Angus 67.15%; black–mottled 42%; Nelore 83.9%; Gir 71,4%. Thus, Bos indicus (zebu cattle) is more promising for the technology of production embryos in vitro, as it exceeds Bos taurus by more than 2 times in the output of oocytes, both in the group of beef cattle and in the group of dairy.