Individually penned Finnish Landrace × Dorset Horn and Suffolk × Scottish Halfbred ewes were used to study the effects of supplementing diets based on ad libitum swedes. Supplementing a pregnancy diet of ad libitum swedes plus 225 g of hay with 454 g of a barley/soya bean meal supplement per day had no effect on swede intake or ewe performance in terms of the birth weight and survival of lambs born. Level of swede intake during late pregnancy was constant. In early lactation, ewes offered ad libitum swedes plus 225 g hay per day were supplemented with 454 g of either barley or soya bean meal daily. Soya bean meal supplementation resulted in a 014 increase in swede intake to give a daily intake of 113g dry matter per kgM 0·7·5 and a total live-weight gain of 218kg in early lactation compared with a loss of 2·53 kg by barley-supplemented ewes. Lamb daily gain increased by 54g per day. The results are discussed in relation to trends towards the housing of ewes and current feeding practices for lactating ewes.