AST, triglycerides and cholesterol in the fluid of ovarian follicles and their relationship with the morphology of the oocyte-cumulus complexes in bovine

Abstract

Oocyte selection is an initial and fundamentally important stage in the technology of producing high quality embryos in vitro. One of the promising approaches in the search for predictors of oocyte quality is the study of the relationship of the biochemical composition of the follicular fluid of cattle with the morphological and functional state of oocytes. The object of the study were: bovine ovaries of black-and-white Holstein breed, fluid of ovarian follicles (FF) and oocyte-cumulus complexes (OCC). Into account were taken: the status of the cumulus - compactness and number of layers, signs degeneration of cumulus cells (sliming cumulus and pyknotic nucleus), homogeneity and color of the oocytes ooplasm, its size, turgor and presence of inclusions. According to these criteria, the oocyte-cumulus complexes were defined as morphologically complete (viable) and not viable. The animals were divided into 2 groups according to the number of viable OCC < 50% of the total number of isolated OCC.The sample size of 21 cows or 42 ovaries. The concentration of cholesterol and triglycerides, as well as the activity of the enzyme aspartate aminotransferase (AST) were determined in the follicular fluid. Biochemical analysis showed that the level of triglycerides and cholesterol in the follicular fluid was higher in the group with a large yield of viable oocytes (P < 0.05). At the same time, the AST concentration is higher in the group of animals with less viable OCC (P > 0.05). The study revealed a correlation between morphologically intact OCC and the concentration of a) triglycerides was r = 0.46 with a confidence factor p = 0.10; b) cholesterol r = 0.69 confidence factor p= 0.01 and C) AST r = - 0.40 confidence factor p = 0.15.