Supplementary feeding of oat grain or lucerne hay to crossbred ewes at lambing

Abstract

Border Leicester x Merino ewes (body condition score 2.6-3.0) grazing short pastures were given feed supplements during lambing, to examine effects on lamb survival. Supplementary feeding of poor quality lucerne hay, good quality lucerne hay or oaten grain, each given ad libitum, began 3 days prior to the start of the 4-week lambing period and continued to the end of lambing. One third of the ewes had twins. Lamb marking percentage for the unsupplemented treatment was 108.5% compared with 109.9, 118.1 and 111.7% for the poor quality lucerne hay, good quality lucerne hay and oaten grain treatments respectively. Of twin-bearing ewes given good quality hay, 60% reared both lambs, compared with 48-49% of those given poor quality hap or grain (n.s.) and 36% of those not supplemented (P < 0.05). Supplements did not improve the survival rate of single lambs. Overall survival (combining birth types) of lambs was also significantly improved by a supplement of good quality hay. The observed differences in twin survival were associated with differences in ewe grazing behaviour. These results support recommendations that supplementary feeding of twin-bearing ewes approaching lambing with a body condition score of 2.6-3.0 will improve lamb survival and weaning weights.