Comparative Evaluation of Different Maturation Media for In-vitro Maturation of Buffalo Oocytes

Abstract

The composition and buffering capacity of maturation media can influence the in vitro maturation of buffalo oocytes. This study compared three commercially available media-BO-HEPES-IVM, BO-IVM, and OMM-under identical laboratory conditions. Buffalo ovaries were collected from a local abattoir and transported in physiological saline at 24–32 °C within 2–3 h of slaughter. Cumulus–oocyte complexes were recovered from 2–8 mm follicles by the slashing technique, graded morphologically, and selected for maturation. Grade A and B oocytes were distributed among three treatment groups in six replicates and cultured in 50 µL drops of maturation medium beneath mineral oil at 38.5 °C in 5% CO₂ for 22–24 h. Maturation was assessed according to cumulus cell expansion and expressed as a percentage. The mean number of oocytes subjected to maturation and the mean number of matured oocytes did not differ significantly among the treatment groups. However, the maturation percentage differed significantly among the media. BO-HEPES-IVM produced the highest maturation rate (90.53 ± 2.61%), followed by BO-IVM (83.72 ± 3.34%) and OMM (77.48 ± 1.65%). The numerical pattern of complete cumulus expansion was consistent with this result. Under the conditions evaluated, BO-HEPES-IVM provided the highest cumulus-expansion-based maturation rate. Further assessment of nuclear maturation and subsequent embryo development is needed before broader conclusions regarding developmental competence can be drawn.