Maternal lysine, methionine and choline supplementation in twin-bearing Merino ewes during mid-to-late gestation does not alter pregnancy outcomes or progeny growth and survival

•Twin lambs have higher mortality than singletons associated with lower birth weight.•Nutritional strategies may increase lamb birth weight and survival via increasing maternal arginine.•Supplementing ewes with rumen-protected lysine, methionine and choline did not increase maternal arginine or lamb survival.