Supplementation with α-tocopherol during in vitro maturation of bovine oocytes and their subsequent embryo development after fertilization

Abstract

To evaluate α-tocopherol supplementation on in vitro maturation of oocytes and their embryonic development, maturation, cleavage, blastulation and blastocyst expansion of 1019 high- and low-quality oocytes supplemented with 100, 200, 400 µL of α-tocopherol or ethanol during maturation were evaluated. Maturation rate of high-quality oocytes was similar in all groups. Low-quality oocytes with 400 μL matured less than 100, 200 μL, control and ethanol. High-quality oocytes with 400 μL cleaved more than 100 μL, 200 μL, control and ethanol. Quality of oocytes in same treatment differed only in the 400 μL group, as high-quality oocytes cleaved more than low-quality oocytes. Blastocysts from high-quality oocytes, expanded more with 400 μL than 100 μL, 200 μL, control and ethanol. With 400 μL, a higher proportion of expanded blastocysts was observed in high and low-quality grades. Addition of α-tocopherol did not show cytotoxicity in terms of maturation rates. Addition of 400 µL of α-tocopherol resulted in higher cleavage and expanded blastocysts rates.