To examine the effects of body condition and previous nutrition on the herbage intake of ewes grazing swards of different heights in autumn, 96 Scottish Blackface X Border Leicester ewes with a wide range of body condition (score 1·75 to 3·50), were initially housed and given 50 g dry matter (DM) per kg metabolic live weight (M)0·75 per day (treatment L) or 95 g DM per kg M0·75 per day (treatment H) of a pelleted dried grass diet (11·6 MJ metabolizable energy per kg DM) for 6 weeks after weaning in July. The H ewes gained more live weight (9·0 v. 2·7 kg) and body condition score (0·39 v. 0·17) than the L ewes. Half the animals from each treatment were then allocated to each of two ryegrass pastures with a sward height of 5 cm (LS) or 10 cm (HS) for a further 6-week grazing period. During the grazing period there was no significant effect of indoor feeding level on herbage intake, but the L ewes gained more live weight (6·4 v. 5·0 kg) than the H ewes. On the HS, compared with the LS sward, mean herbage intakes were higher (70·0 v. 60·5 g DM per kg M0·75) as were gains in live weight and condition score (7·9 v. 3·4 kg; 0·18 v. 0·0). There were no interactions between the effects of sward height and previous feeding level on herbage intake. Ewes in low body condition (< 2·5) at the start of the grazing period ingested the same amount of herbage on both swards (70·3 g DM per kg M0·75) whereas ewes in high body condition (> 2·5) ingested more (67·0 v. 51·6 g DM per kg M0·75) on the HS compared with the LS sward. The responses of ewes in low and high body condition to different sward heights are discussed in relation to appetite drive and aspects of grazing behaviour.

A 3-year experiment was carried out to compare systems of bull beef production involving continuous housing or pasture grazing from 5 to 10 months of age and to examine the effects of herbage allowance and concentrate supplementation on lifetime performance and carcass quality. Animals were either set-stocked at pasture to maintain nominal sward heights of 7, 9 and 11 cm or were offered grass silage (700 g digestible organic matter per kg dry matter (DM)) supplemented with 1·5 and 3·0 kg barley-based concentrates (183 g crude protein per kg DM) per head daily. Half of the animals grazed at each sward height were given 1·5 kg concentrates per head daily while the remainder received no supplement. A total of 160 continental X Friesian and 48 Friesian calves which were initially 197 kg live weight were used. From 10 months of age until slaughter at about 17 months all animals were given grass silage ad libitum and supplemented with 3·0 (year 1) or 3·75 (years 2 and 3) kg cereal-based concentrates per head daily.

Animals which grazed the 9- and 11-cm swards produced carcasses of similar weight to those given silage and 3·0 kg concentrates per day, while those grazing the 6·7-cm swards produced carcasses of similar weight to those given silage supplemented with 1·5 kg concentrates. Reducing sward surface height from 11·0 to 9·3 cm did not affect performance but further reductions to 7·9 (year 1) and 6·7 (years 2 and 3) cm reduced live-weight gain by 0·13 and 0·32 kg/day respectively. Concentrate supplementation did not affect the performance of animals grazing swards which were 7·9 cm or taller but increased live-weight gain by 93 and 193 g/kg concentrates for those grazing the 6·7 cm swards and those receiving silage respectively. Differences in live weight at 10 months of age due to the feeding treatments imposed from 5 to 10 months of age were largely retained until slaughter at 17 months as there was little compensatory growth during the residual period. The treatments did not affect carcass composition when the data were adjusted to a constant carcass weight, or meat quality which was satisfactory for all treatments.