A comparison of the carcass quality of Romney with Border Leicester × Romney lambs and Southdown × Romney with Southdown × (Border Leicester × Romney) lambs

Abstract The carcass composition of Border Leicester × Romney wether lambs was compared with that of Romney wether lambs in two seasons. There were no significant differences in carcass composition between the two groups of lambs born in 1963 when the lambs were grazed from birth to slaughter on hill country. However, the Border Leicester × Romney wethers were heavier and significantly fatter than the Romneys for the 1964‐born lambs which were transferred after weaning to lowland pastures. Covariance analysis indicated that this difference in composition could be explained by differences in carcass weights. The carcass composition of lambs, produced by mating first‐cross Border Leicester × Romney or Romney ewes with Southdown rams, was compared in two years. Lambs from the first‐cross ewes had heavier carcasses in both years and were significantly fatter in the first when they were older and heavier than in the second. This difference in fat content remained significant after covariance adjustment for carcass weight. Jointing data indicated no important breed differences in conformation within the hill country or export lamb groups.