The application of the technique of egg transfer to sheep breeding

Abstract

During the autumns of 1960 and 1961, 86 first- and second-cross (backcross to polled rams) polled Merino ewes were treated with a horse anterior pituitary extract (HAP) to induce multiple ovulation. Of the 86 ewes, 78 were served within 96 hr of the cessation of treatment. Laparotomies, performed for the pqrpose of egg recovery, showed that 74 of the ewes served had ovulated, shedding a total of 841 eggs of which 667 were recovered and of these 482 had been fertilized. A total of 441 fertilized eggs were transferred at rates of one to three per animal to the uterine horns or Fallopian tubes of 262 recipient horned Merino ewes of which 177 subsequently lambed, producing 236 lambs. Irrespective of the number transferred per recipient, the proportion of eggs which developed into lambs following tuba1 transfers was significantly less than that following uterine transfers. The survival of transferred eggs was not significantly affected by the number transferred per recipient. The practical value of the technique of egg transfer in the ewe is briefly discussed.