Authors: ABID MEHMOOD, MUHAMMAD ANWAR, SAYED MURTAZA HASSAN ANDRABI, MUHAMMAD AFZAL, SYED MUHAMMAD SAQLAN NAQVI
Abstract: Conditions for in vitro maturation (IVM) of primary oocytes without conventionally used fetal calf serum and hormones were optimized in order to reduce the cost of laboratory produced buffalo embryos. Comparisons were made between oocyte recovery methods (aspiration vs. slicing) and IVM in medium 199 (static culture method vs. flux culture method) supplemented with 4-5 × 106 granulosa cells mL-1 that contained either estrus buffalo serum (EBS) or fetal calf serum (FCS). Recovery methods were compared according to yield, i.e. cumulus oocyte complexes per ovary (COCs/ovary), the expansion rate (% of COCs that expanded), and nuclear maturation rate (% of germinal vesicle breakdown [GVBD]), following IVM for 22-24 h. In vitro maturation methods (static culture with EBS or FCS and Flux culture with EBS or FCS) were compared on the basis of the expansion rate and in vitro fertilization rate (cleavage rate). COC recovery with the slicing method (2.2 COCs/ovary) was better (P < 0.05) than with aspiration (0.9 COCs/ovary). However, the IVM rate was better (P < 0.05) based on expansion (86% vs. 63%) and GVBD (85% vs. 62%) with aspiration than with the slicing method. The cleavage rate (37%) was significantly better with the static culture containing EBS than with the static culture with FCS or the flux culture with either EBS or FCS. It was concluded that aspiration of oocytes and subsequent IVM with static culture containing EBS would be a potential method to reduce the cost of laboratory produced buffalo embryos.
Keywords: Buffalo, oocyte, aspiration, slicing, serum
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