Taylor (1980) indicated the importance of mature size in the description of animals and its usefulness for standardising growth parameters. The mature size and body composition of the Gallego breed, a small meat-producing type first described by Mason (1967), have never been estimated under defined management conditions. Therefore, using the scaling rules and results of Thonney, Taylor, Murray and McClelland (1987) as a guide, a study was made to determine whether the reputation of Gallego lambs for producing lean carcases was borne out in the composition of mature animals.

Twenty-one ewes (mean liveweight, LW, 32.7, sd 5.4 kg) and eight rams (LW 47.6, sd 8.6 kg) were selected as cast animals on the basis of age ( >4 years), body condition score (BCS, >1.75), health and teeth status and group-fed on concentrate (180 g crude protein/ kg dry-matter) and hay ad libitum. LW was measured fortnightly. When all animals had a LW and BCS which were stable for 2 months, 3 subgroups were slaughtered monthly. Weights of wool, body organs and hot carcase (HC) were recorded. Dissection of the cold carcase (CC) into commercial joints (Cabrero Poveda, 1984) and total lean, bone and fat.