DETERMINATION OF EFFECTIVE MEDIA AND ITS HORMONE SUPPLEMENTATION ON IN VITRO MATURATION AND FERTILIZATION OF COW OOCYTES

Abstract

The present experiment was conducted to determine an effective basic medium and its hormone supplementation for in vitro maturation and fertilization of cow oocytes. To determine an effective basic medium and hormone the effect of Tissue Culture Media 199 (TCM 199), Tissue Culture Media 199 (TCM 199) supplemented with different doses of Gonadotropin (0.5, 1,5,10 and 15 µg/ml) hormone on in vitro maturation and fertilization (of cow oocyte were evaluated throughout the study. Synthetic ovurulin used as substitute of gonadotropin. Cumulus Oocytes Complexes (COCs) were collected from cow ovaries by aspiration method and matured for 48 hours at 37.5ºC with 5% CO 2 in humidified air in basic and supplemented media. Significantly higher (p<0.05) number of follicles were aspirated in ovaries without CL (Corpus Luteum) (4.59±0.27) compared with ovaries containing CL (3.05). Consequently higher numbers of COCs were found in ovaries without CL (4.61) than ovaries with CL (1.98). The maturation rate was significantly higher (65.71) in (TCM 199 with Gonadotropin10 µg/ml) medium than those of other treatment. Higher maturation rate was found up to the 10 µg/ml Gonadotropin supplementation but when the dose exceeds 10 µg/ml the maturation rate began to decline. In vitro fertilization rate depends on, the condition of the used semen whether it is fresh or frozen, oocyte quality and maturation rate. Comparatively higher fertilization rate based on pronucli formation was found in Tissue Culture Media 199 (TCM 199), supplemented with Gonadotropin 10 µg/ml (40.14) than other media. Therefore, ovaries without CL could be used in Tissue Culture Media 199 (TCM 199), basic medium supplemented with Gonadotropin (10 µg/ml) level may be used as a basic medium for optimum in vitro maturation rate of cow’s oocytes in Bangladesh.