Reproductive performance of Merino ewes supplemented with sweet lupin seed in southern Western Australia

The effect of supplementation of mature Merino ewes, with 250 g of sweet lupin (Lupinus angustifolius L.) seed/head.day from 14 days before joining until day 17 of joining, on flock prolificacy was evaluated under commercial farming conditions over 3 years in a series of 50 trials involving 22 800 ewes. Responses to supplementation, in terms of lambs born, ranged from - 14 to + 2 1 %. Increasing the rate of supplementation to 500 g/head.day did not overcome the problem of the variable response. The present inability to select responsive situations limits the potential use of supplementation with lupins to increase the reproductive performance of Merino ewe flocks.