Two hundred and fifty Border Leicester x Merino ewes (40% heterozygous for the Booroola Fec B gene) were used in an experiment, replicated over 2 years, to examine the effects of cottonseed meal-based supplementation on lamb survival, birth, marking and weaning weight, as well as, liveweight and fleece characteristics of ewes. From 50 to 100 days of pregnancy, half of the ewes were supplemented with 80 g/head.day. The supplemented group was then split according to litter size and, until 30 days after lambing, were offered pellets at 80, 160 and 220 g/head .day, respectively, for ewes bearing single, twin and triplet (or more) lambs. Over the 2 years, ewes averaged 2.11 lambs per parturition and supplementation significantly increased lamb survival to weaning (73 v. 58%) with no interaction with litter size. Although supplementation had a positive effect on birth weight of all but twins, the effects of supplementation on survival were independent of birth weight effects. Significant effects of year, sire breed and litter size on lamb survival and birth weight were also noted. No effects of supplementation were apparent on lamb growth while ewe age, sire breed, sex and rearing rank all significantly influenced growth rates. Ewe weights, fleece weights and staple strength were significantly influenced by year, ewe age and litter size but not by supplementation. These findings indicate the benefits to lamb survival of providing a 'bypass' protein supplement to high fecundity flocks even when ewes are grazing good quality pastures.

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One hundred and thirty-one pregnant, parous Border Leicester x Merino ewes at pasture were supplemented with a mixture of lupin and oat grain for a minimum of 3 weeks prepartum, and an average of 1 week post-partum in a lamb production experiment. Supplement was group-fed daily at a rate of 400 g/ewe. Pasture and grain intake were determined on 1 day, at an average 7 days prepartum. On an individual ewe basis, there was considerable variation in supplement intake with 11% of ewes consuming <200 g/day and 10% consuming >700 g/day. Significantly (P<0.01) more supplement but less pasture (P<0.05) was eaten by twin-bearing ewes (440 � 23 g) than single-bearing ewes (340 � 36 g). Total feed intake was similar with less variation than in supplement or pasture intakes. Results suggest lower pasture intakes in twin-bearing ewes can be compensated by higher grain intakes which means that separation of single- and twin-bearing ewes may not always be warranted in a supplementation program.

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