Housed male (stags) and female (hinds) red deer, initial live weight 43·2 and 38·3 kg respectively, were given ad libitum (1) ammonia-treated straw, (2) a barley and fish meal concentrate, and hay, or (3) potatoes and hay, from 7 to 11 months of age. Dry matter (DM) intakes were low for all deer and some live-weight loss was experienced for the first 6 weeks in January/February. Thereafter DM intakes increased, and deer given the concentrate diet showed higher live-weight gain (P < 0·001) than those given potatoes and hay (273 and 162 g/day, respectively) whereas deer receiving the treated straw continued to lose weight (-18 g/day) (P < 0·001).

From 11 to 16 months of age at grass, deer previously given treated straw grew significantly faster (P < 0·001) than those previously overwintered on concentrate or potato diets (215, 156 and 170 g/day, respectively). Final live weights for animals given straw, concentrates and potatoes in the preceding winter were, respectively, 71·6, 92·6 and 80·8 kg (stags) and 63·0, 71·9 and 68·5 kg (hinds).

The dietary treatments imposed in the previous winter had no lasting effects on the carcass composition of stags slaughtered at 16 months, and the practical implications of the different growth patterns are discussed.