EFFECT OF BOVINE SERUM ALBUMIN ON IN-VITRO MATURATION OF BOVINE OOCYTE

Abstract

The present experiment was to investigate the effect of different concentration of Bovine Serum Albumin on in vitro maturation of bovine oocyte. Cumulus oocytes complexes (COCs) were collected from bovine ovaries by aspiration method and matured for hours in TCM-199 basic medium supplemented with different concentration of BSA 10% and 15%). The Significantly higher (p<0.01) number of follicles were aspirated in ovaries without CL (Corpus Luteum) ±0.28) than with CL containing ovaries (3.00±0.37). Higher numbers of COCs were found in ovaries without CL (4.42±0.30) than ovaries with CL (2.40±0.40). Number of follicle aspirated in left ovaries (4.76±0.20) and in right ovaries (4.74 ±0.20).The collected number of COCs higher in left ovaries (4.47±0.19) compared to right ovaries (4.34±0.18).Three levels of cumulus cell expansion after hours of in vitro maturation (at 38.5 °C and 5% CO in an incubator) observed under 10x magnification of microscope and different stages of nuclear maturation was observed based on chromosomal configuration. Oocytes reached to Level-1, Level-2 and Level-3 cumulus cell expansion level with 0% 10% and 15% of BSA concentration were 0.32%, 0.26%, 0.29% and 0.50%; 0.38%, 0.43%, 0.86% and 0.31%; %, 0.71% and 0.06% respectively, where, 5% BSA supplementation was reached 0.96% at cumulus cell expansion level- The percentage of COCs reached to Metaphase-I, Metaphase-II, GVBD (germinal vesicle break down) and GV(Germinal vesicle) stages with 0%, , 10% and 15% of BSA supplementation were 0.00%, 0.92%, 0.47% and 0.28%; 0.12% and 0.00%; 0.64%, 0.62%, 0.82% and 0.61%; 0.29%, 0.24%,and 0.44% respectively. These result further indicate that the maturation and subsequent development rate could be significantly increased (p<0.01) by supplementing 5% level of BSA than that of control. This trend maintained up to 10% of BSA, but no further improvement was found by increasing level of BSA up to 15%. It is conducted that the left ovary without CL is a good source of normal grade oocytes and 10% level of BSA supplementation has a positive effect of in vitro maturation of bovine oocytes.