INVITRO MATURATION AND FERTILIZATION OF BUFFALO OOCYTES (BUBALUS-BUBALIS) - EFFECTS OF MEDIA, HORMONES AND SERA

Media (TCM-199 and Ham's F-10 ) ; sera (fetal calf serum, FCS, and buf falo estrous serum, BES ) ; and hormones (FSH, 0. 5 ug/ml, LH, 5 ug/ml and estradiol 1 ug/ml) were tested to determine the efficiency of in vitro maturation and fertilization of buffalo follicular oocytes. Imma ture good quality cumulus-oocyte complexes (COCs) were randomly assign ed to 1 of 4 experiments. Each experiment consisted of 6 treatment gro ups. oocytes cultured for 24 hours in medium (TCM-199 or Ham's F-10 ) containing 10% FCS or BES had a significantly higher maturation rate t han those in medium alone (P < 0.05). However, the maturation rate was higher in medium supplemented with 10% FCS than with 10% BES. Additio n of hormones alone or in combination with sera further improved the m aturation rate, but no significant difference was observed in the matu ration rate among the 3 hormone-treated groups. Immature oocytes matur ed in the various cultures were fertilized with frozen-thawed buffalo spermatozoa.our findings show that hormone and/or serum supplementatio n of TCM-199 did not improve the fertilization rate. Supplementation o f Ham's F-10 with LH alone or in combination with LH + FSH + E2 and wi th FCS significantly improved the fertilization rate of oocytes while medium with FSH, E2 or no hormones did not ( P < 0.05) ; same media su pplemented with BES resulted in lower fertilization rates both in the presence or absence of hormones. The results indicate that the culture medium has a marked effect on the fertilization rate of buffalo oocyt es. Ham's F-10 + LH + FSH + E2 supplemented with FCS was the most effi cacious culture system of those studied for the in vitro maturation of buffalo oocytes.