EFFECT OF OXYTOCIN TREATMENT DURING ESTRUS ON THE OVULATION RATE OF MERINO EWES

The effect of oxytocin treatment on the ovulation rate Of Merino ewes was investigated. Intravenous doses (0.1 IU) of oxytocin were administ ered to synchronised ewes (n = 54) every 30 min for a 24 h period begi nning at the onset of oestrus. Laparoscopic examination of the ovaries of all ewes that bad displayed overt oestrus following sponge withdra wal was performed 10 d after the beginning of oxytocin treatment to de termine the number of corpora lutea per ewe. The ovulation rates of th e treated and control groups were 174.5% and 144%, respectively (p < 0 .01). It would appear that a higher ovulation rate can be obtained by repeated low-dose intravenous injection of oxytocin during oestrus.