Abstract
Weights and measurements were taken on 2,326 lamb carcasses during the summer, fall and winter of 1967 to 1968 at each of six packing plants in the Rocky Mountain region in order to determine amount of finish on carcasses in different weight groups. Effects of season of year, sex, breed, grade and management on amount of finish were also analyzed. In general, as carcass weight increased there was an increase in percent kidney fat, fat over the l. dorsi and bodywall thickness. As a result of increased fat, estimated percent retail yield decreased slightly as weight increased. Approximately one-third of the carcasses weighed over 25.3 kg. and would be considered too heavy by most retailers. Of the 820 heavy carcasses weighing 25.4 to 29.8 kg., about 80% were considered properly finished. Approximately 10% of all the carcasses were considered overfinished, and of these 82% were also over 25.3 kilograms. It was concluded, therefore, that the majority of overfinished carcasses are usually over 25 kg., but the majority of carcasses over 25 kg. are not overfinished. Least square analysis showed ewes with more kidney fat, more fat over the l. dorsi and thicker bodywall measurements than wether lambs. Prime carcasses had significantly (P<.05) more finish than Choice carcasses. Whiteface lambs had more kidney fat and thicker bodywalls than blackface cross lambs. Farm flock and feedlot lambs had more fat over the l. dorsi than range or field fed lambs. Farm flock lambs had significantly (P<.05) more kidney fat and thicker bodywalls than lambs in any other management practice studied. When unidentified retail cuts were placed side by side in self-service counters, consumers selected rib and loin chops from 30 kg. carcasses by a ratio of 6:5 over similarly finished rib and loin chops from 23 kg. carcasses. There were no significant differences in selection of blade and arm chops from carcasses of the two weight groups. Leg roasts from 23 kg. carcasses were selected by a ratio of approximately 3:1 over leg roasts from 30 kg. carcasses. When extra sirloin steaks were cut from the heavier legs, they weighed approximately the same as the lighter legs and, under these conditions, no difference in consumer selection of leg roasts was noted. Copyright © 1969. American Society of Animal Science . Copyright 1969 by American Society of Animal Science