Barley grain supplementation in late gestation to improve lamb survival in twin-bearing Merino ewes grazing pasture of high biomass and quality

Lamb mortality from birth to weaning is the most prominent factor leading to the poor reproductive performance of Merinos. Providing a high starch feed prior to lambing can increase colostrum production, which has the ability to increase passive immunity transfer to the lamb following birth, increasing survival. To determine whether lamb survival to marking was increased by this method when grazing abundant pasture, naturally joined twin-bearing Merino ewes (n=240) were supplemented with barley grain in the last two weeks of gestation and first two weeks of lambing. Lamb survival (81%) was similar in supplemented and control treatments. This study indicates that when large quantities of quality pasture are available there may be no increase in the survival of twin-born lambs due to barley grain supplementation of ewes.