Effect of nutrition on the response in ovulation rate in Merino ewes following short-term lupin supplementation and insulin administration

Abstract

In experiment 1, groups of Merino ewes, 4-6 years old, were given daily wheat chaff 500 g plus vitamin and mineral supplements, or wheat chaff 800 g and pelleted feed containing lucerne, lupin and barley 350 g plus mineral and vitamin supplements. Diets provided 0.5 and 1.2 times maintenance requirements. On each plane of nutrition, lupins 750 g were given or not given 10 days before oestrus. In experiment 2, the same planes of nutrition were used and sheep were injected daily with insulin 15 IU, or left untreated. Ovulation rate increased in response to lupin feeding at both planes of nutrition. Exogenous insulin, given as a daily single injection did not increase ovulation rate.