IN VITRO MATURATION, FERTILIZATION AND DEVELOPMENT OF PREPUBERTAL AND MATURE BUFFALO OOCYTES

SUMMARY The competence of pre-pubertal buffalo heifers’ oocytes for in vitro maturation, fertilization and development were studied and compared with that of the adult buffalo oocytes. Ovaries were collected from local abattoir. The oocytes were recovered from antral follicles (3-8 mm) in diameter by aspiration technique and cultured in TCM-199 medium supplemented with 10% fetal calf serum(FCS), 10 IU/ml PMSG , 20 IU/ml LH , 1 μg/ml Estradiol 17 β and 50 μg/ml Gentamycin sulfate and incubated in 5% CO2 and high humidity for 24 h at 38.5°C. Number of antral follicles per ovary were insignificantly higher on heifer's ovary (7.00 ± 0.74) comparing with adult buffalo cow's (6.45 ± 0.34). The recovered immature oocytes per ovary were higher, (P<0.001) in buffalo heifers than that in the adult ones (4.35 ± 0.28 and 2.99 ± 0.14, respectively). The competence of immature recovered oocytes to resume meiosis and reach metaphase II were lower (P<0.01) in heifer's ovaries (28.3%) compared to that of the adult cows (59.6%). The fertilized and developed oocytes reached the transferable stages were nearly the same rate in both adult buffalo cow and heifers (26.3 and 27.4%, respectively). Cleaved oocytes were insignificantly low in the heifer group (55.3%) from the initial cultured oocytes number compared with that of the adult group (64.5%). It can be concluded that the pre-pubertal heifers could be a good source for oocytes needed for IVF techniques.