Culture and fertilization of sheep ovarian oocytes:IV. Observations on sperm penetration in oocytes transferred to the sheep oviduct

Abstract

SUMMARYTransfer was made of 2958 sheep ovarian oocytes, cultured in growth medium for 24–30 h, to the oviducts of 142 oestrous sheep; 132 were bred and ten remained unbred. Forty-two per cent of oocytes were recovered, mainly 4–24 h after transfer; tubal flushings were examined for sperm. Evidence of a sperm within the vitellus of follicular oocytes was found in nine recipients, the earliest at 6 h 50 min after transfer. Pronucleate eggs were most frequent 9–14 h after transfer; a limited number of eggs showing normal cleavage wasrecovered.