Some sources of variation in tenderness and cooking losses in lamb and mutton

摘要

Abstract Six experiments are reported involving 218 Southdown-Romney cross ewe and wether lambs slaughtered at either 15 weeks or 9 months of age, and 136 Romney wethers slaughtered at 16 months of age. The tenderness of the meat of these animals was assessed with a mechanical tenderometer on duplicate samples of the cooked longissimus dorsi muscle of the left side. Differences in tenderness attributable to sire and pasture type were considered. Although sire effects were not consistently significant, the moderately repeatable ranking of sire groups in two consecutive years suggests that selection for tenderness in sheep would be effective. Pasture effects, however, were neither significant nor repeatable. All experiments were characterised by the large proportion of residual variation (83%, 98%, and 72% in Experiments 1, 2, and 3, for example) after a number of correction factors had been applied. This was attributed mainly to variations between animals in the way in which they reacted to treatment immed...