Culture and fertilization of sheep ovarian oocytes:III. Evidence on fertilization in the sheep oviduct based on pronucleate and cleaved eggs

Abstract

SUMMARYFour hundred and fifteen oocytes cultured in growth medium for 24·5–28·5 h were transferred to the oviducts of 23 oestrous ewes. Twenty ewes were bred prior to transfer; three remained unbred as a control. After intervals of 24–73 h oocytes were recovered. In 179 oocytes from 19 bred recipients, 19 pronucleateand 26 cleaved eggs were recovered; one apparent 4-cell egg was found in 37 oocytes recovered from unbred ewes.