Effect of in vitro Fecundation of Prepubertal Sheep Oocytes With or Without Cumulus Cells on Cleavage and Embryo Development Rate: A Comparative Study of Bovine Serum Albumin and Sheep Serum Added to the Capacitation Media

The aim of this work was to study the effect of Bovine Serum Albumin (BSA) and Sheep Serum (SS) on seminal capacitation medium in accordance with division rate and embryo development of female lamb in vitro maturated oocytes with (COCs) or without cumulus cells (ODs). The capacitation medium was synthetic oviductal fluid (SOF) supplemented with 2.38 mg/mL Hopes and 25 mu g/mL Gentamicyne, with either 4 mg/mL BSA or 20% (v/v) SS. Sperms used for fecundation were isolated by swim up, with 1 x 10(6) sperms/mL concentration. Cleavage rate and embryo development were observed at 48 and 168 h post insemination, no finding any significant influence of the capacitation medium tested (BSA vs SS): 21.5 vs 24.3% for COCs and 10.8 vs 8% for ODs on cleavage rate, or on development 16.7 vs 16.6% for COCs and 2.1 vs 8.8% for ODs. Nevertheless, the oocyte type significantly influenced (P<0.001) the maturation rate, COCs oocytes got better maturation rates than ODs; 69.5 vs 31.1%, respectively. These results confirm that both BSA and SS are good capacitation agents for in vitro embryo production protocols. On the other side, it confirmed that removal of cumulus cells prior in vitro maturation reduces maturation, cleavage and embryo development rates. However, a part of these oocytes get develop to the morula stage, so it can't be reject to be used in combination with new reproductive techniques.