The effect of frequency of feeding a lupin grain supplement at mating on the reproductive performance of maiden and mature Merino ewes

Abstract

Two groups of South Australian strong-wool Merino ewes, each consisting of maiden and mature ewes, were supplemented with lupin grain either once or three times weekly. Both groups received 1.75 kg of supplement per head per week from two weeks before joining to three weeks after joining. A third group of ewes received no supplement. All groups grazed a cereal stubble. Mature and maiden ewes supplemented once weekly and maiden ewes supplemented three times weekly did not respond in ovulation rate, fertility or fecundity. However, the mature ewes supplemented three times weekly had a 16 per cent higher incidence of multiple ovulations (0.05 < P < 0.1), an 11 per cent higher ovulation rate (ns.) and a 21 per cent higher fecundity (P < 0.05) than unsupplemented mature ewes. Under the conditions of this experiment we conclude that the supplement needs to be offered more frequently than once weekly to stimulate reproductive activity.