The Recovery, in Vitro Maturation and Fertilization of Nili-Ravi Buffalo Follicular Oocytes

Abstract

Four types of serum supplements viz estrus cow serum (ECS), estrus buffalo serum (EBS), proestrus buffalo serum (PrBS) and post-estrus buffalo serum (PtBS), added to TCM-199, were evaluated for in vitro maturation and fertilization of buffalo follicular oocytes. The oocytes were recovered from buffalo ovaries after slaughter, using either aspiration or scoring (multiple incisions) method. The recovered oocytes were categorized as A, B and C based on their cumulus investment and ooplasm homogeneity and cultured in four media. The in vitro matured oocytes were inseminated with 1 × 106 spermatozoa washed in 2.9% sodium citrate solution. The scoring method yielded greater number of morphologically good oocytes than the aspiration method (3.85 vs 1.76 per ovary, p < 0.01). The maturation rates of three categories of oocytes did not differ from one another. The maturation rates of 80.00, 82.08, 78.77 and 66.23%, while the fertilization rates of 54.54, 55.38, 52.80 and 36.76% were recorded for media containing ECS, EBS, PrBS, and PtBS, respectively. The medium containing PtBS gave lower maturation, as well as fertilization, rates than the other three media (p < 0.05). Thus, the scoring method was better than the aspiration method for the recovery of follicular oocytes. The oocytes categorized A, B and C had similar maturation capabilities. The TCM-199 containing buffalo/cow serum collected at pro-estrus or estrus appeared better for in vitro maturation and fertilization of buffalo follicular oocytes than that containing serum collected at post estrus.