author(s)
Trilok Gocher, Govind Narayan Purohit and Sasi G

abstract
This study was carried out to compare the effect of supplementing maturation medium with different antioxidants on the in vitro maturation of immature oocytes. In order to evaluate the effects of antioxidants culturable grade oocytes (total 528) were matured in vitro in TCM-199 (with 20 IU/ml eCG, 20 IU/ml hCG, 1 µg/ml estradiol, 25 mM Hepes, 0.25 mM pyruvate and antibiotics) that was randomly supplemented with either 10 µg/ml of melatonin (MLT), 50 µg/ml of L-ascorbic acid (LAA), 1mM taurine (TAU) or without any antioxidants (Control) for 28 hours. On completion of in vitro maturation the oocytes were evaluated for cumulus expansion and nuclear maturation. The best cumulus expansion (+++) was achieved in TCM-199 medium supplemented with MLT followed by LAA supplementation. After evaluation of cumulus expansion, the same oocytes were freed of cumulus cells, fixed, stained and assessed for nuclear maturation. Significantly higher (P<0.05) proportions of oocytes were matured in vitro in medium supplemented with MLT compared to medium supplemented with LAA, TAU and control. It was concluded that enriching the maturation medium with melatonin or L-ascorbic acid improves the cumulus cell expansion of in vitro matured goat oocytes and melatonin also improves the nuclear maturation.