Studies in ovine infertility in agricultural regions in Western Australia: the influence of a supplement of lupins ( Lupinus angustifolius cv. Uniwhite) at joining on the reproductive performance of ewes

The dietary supplementation of groups of 200 ewes with lupins (0.23 or 0.45 kg per head per day) just prior to and during joining increased the ovulation rate by 8–25 ovulations per 100 ewes and the number of lambs born increased by 5–23 lambs per 100 ewes joined. The increase in the number of lambs born had two components: (i) an increase in number of ewes lambing and (ii) an increase in the number of twin births. Another study suggested that feeding the lupin supplement during joining gave larger increases in the reproductive performance of the ewes, especially in number of ewes lambing, than feeding the supplement of lupins before joining. The increases in reproductive performance following lupin supplementation were not associated with differences or changes in body weight or with differences in the rate of wool growth. The feeding of a barley + urea + mineral supplement that provided 25% more digestible energy than the lupin supplement and similar nitrogen levels, but with 50% of the nitrogen in the form of urea, resulted in no increase in the reproductive performance of the ewes.