EVALUATION OF FERTILITY STATUS OF MURRAH BUFFALO BULLS IN-VITRO USINGZONA-FREE HAMSTER EGGS

Cryopreserved semen samples from 10 Murrah buffalo bulls were used for sperm penetration bioassay using zona-free hamster oocytes. The sampl es were evaluated for sperm motility, viability and acrosome integrity . Actively motile spermatozoa recovered by the swim-up technique were capacitated using calcium ionophore A(23187). Mature female golden ham sters were superovulated with 50 IU PMSG followed 56 h later by 75 IU hCG. Cumulus mass, recovered by puncture of oviducts at the infundibul um region, was treated with 0.1% hyaluronidase and 0.1% trypsin to obt ain zona-free oocytes. After coincubation of zona-free oocytes with ca pacitated buffalo spermatozoa, scoring was done as fertilization perce ntage and fertilization index. The correlation coefficients with conce ption rate were statistically significant with fertilization percentag e (r = 0.588, P < 0.05) and fertilization index (r = 0.660, P < 0.01). However, conventional parameters like viability, motility and acrosom e integrity showed poor correlation with conception rate. (C) 1997 by Elsevier Science Inc.