STUDY ON THE IN VITRO PRODUCTION OF BUFFALO EMBRYO (MURRAH SWAMP BUFFALO)

Abstract

The studies on in vitro production of crossbred buffalo embryo (Murrah x Swamp buffalo) were undertaken. Ovaries were recovered from the slaughterhouse. Oocytes collected were classified A, B and C according to their quality and only the oocytes grade A or B were used for the experiments. Cumulus oocyte complexes (COCs) were cultured for in vitro maturation for 24 hrs (38.5'C, 5%CO" humidified air) in medium MAT-I (without EGF) or MAT-2 (with EGF). Frozen-thawed Murrah sperms were treated by swim-up or gradient Percoll procedure. In vitro fertilization (selected Murrah sperm and matured Swamp buffalo oocyte) was carried out in the medium IYF-I (supplied 10 fig Heparin/ml) or IVF-2 (supplied 20 fig Heparin/ml) for 24 hrs (38,5'C, 5%CO2 humidified air). Buffalo zygotes were subsequently cultured in B2 medium (38.5'C, 5%CO" humidified air). Our results show that EGF influences positively on the development of oocyte during the in vitro maturation, the quality of oocyte have a great effectiveness on the rate of matured oocyte and the result of in vitro fertilization. The proportion of matured oocyte reaches 69,64% in MAT-2 medium, significantly higher than that of 57.23% in MAT -1 medium (P < 0.01). For treatment of sperm prior to in vitro fertilization, the optimal time of swim-up and gradient Percoll process is about 60 minutes and 20 minutes,  espectively. We obtained the similar cleavage rate of buffalo embryo at 2 cell stage in two media IYF-I and IVF-2 (51.92% and 50.41%, respectively).