Effect of cysteamine and epidermal growth factor supplementation on the in vitro maturation rate of ovine oocytes

Abstract Ovaries of slaughtered ewes ( n  = 78) were collected from abattoirs in Srinagar city, India and transported to the laboratory in a normal saline solution containing 50 μg Gentamicin sulphate per ml—to study the effect of cysteamine and epidermal growth factor (EGF) supplementation in the maturation medium on the in vitro maturation rate of ovine oocytes. The slicing technique was used to recover oocytes from the large (>2 mm diameter) follicles and the acceptable oocytes were washed twice and matured in 2–3 ml of the different maturation media i.e. control (TCM-199 containing 10% FCS, 10 μg FSH per ml and 50 μg Gentamicin sulphate per ml), M1 (control + 200 μM cysteamine per ml) and; M2 (control + 20 ng EGF per ml). The total number of usable oocytes utilized to compare the maturation rate of the control, M1 and M2 medium were 75, 76 and 76, respectively, with the maturation rate of the oocytes being 62.7%, 65.8% and 82.9%, respectively. The in vitro maturation rate was significantly higher for the EGF containing medium (M2), compared to the cysteamine containing media (M1) and the control (C). It may thus be concluded that EGF should be encouraged as a supplement for the in vitro maturation of ovine oocytes.