Effect of Varying Live Weight and Preslaughter Fast Period on the Slaughter, Storage, Cutting and Cooking Losses of Lambs2

Eighty-six lambs were slaughtered at 33, 40,50 or 60 kg. preshrunk, shorn live weight after being fasted for 24 or 72 hr. Marketing losses were determined to include preslaughter, slaughter, cooler and cutting losses. Cooking losses were then determined on representative loin chops from each lamb. Although body weight significantly affected all marketing losses measured, these were often offsetting effects, and the percent of the original lamb, ranging from 32.7 to 34.6, included in the four trimmed retail cuts (leg, loin, rack and shoulder) was not greatly affected by body weight in the lambs fasted for 24 hr. The range was greater (30.7 to 34.1%) in the lambs fasted 72 hr., as a reduction due to fasting was noted in the lightest lambs. The chemical composition of the wholesale rack and retail loin chops was affected by body weight. Cuts from the larger lambs were higher in ether extract and lower in water, protein and ash content. Cooking tended to diminish these differences. No differences due to preslaughter shrink period were noted on cooking losses.