Characteristics of carcass and of non-carcass components of lambs and hoggets fed high-concentrate corn or sorghum diets

ABSTRACT The objective of this study was to evaluate the characteristics of carcass and non-carcass components of lambs and hoggets finished in the feedlot with high-concentrate corn or sorghum grain-based diets. Thirty-two animals were finished, comprising 16 lambs (milk teeth) and 16 hoggets (two teeth), which were distributed in a completely randomized design in a 2 × 2 factorial arrangement (two sheep categories × two grains). For the variables final live weight, live weight at slaughter, hot carcass weight, cold carcass weight, hot carcass yield, cold carcass yield, carcass compactness index, subjective color, loin-eye area, fasting losses, external organs, internal organs, and for the weights, in kilograms, of neck, shoulder, ribs, and leg, there was a significant difference between categories. In the variables studied for the high-concentrate diets, significant differences were found for the ribs, expressed in relative values. Lambs have much higher fasting losses, a greater proportion of internal organs, and lighter-colored meat compared with hoggets. Hot and cold carcass yields, meat subjective color, and percentage of ribs are higher in feedlot-finished lambs and hoggets fed high-concentrate sorghum-based diets compared with those fed corn-based diets.

摘要
本研究旨在评估饲喂高浓缩玉米或高粱谷物型日粮的舍饲育肥羔羊与两齿周岁羊的胴体（carcass）与非胴体（non-carcass）组分特性。本试验共纳入32只育肥羊，包含16只乳齿羔羊与16只两齿周岁羊，采用2×2析因完全随机试验设计（2个羊类别×2种谷物原料）。
针对终末活重、屠宰活重、热胴体重、冷胴体重、热胴体率、冷胴体率、胴体致密性指数、肉色主观评分、眼肌面积、绝食失重、外器官重量、内脏器官重量，以及颈、肩、肋、腿部位重量等变量，不同羊类别间均存在显著差异。
在高浓缩日粮的相关研究变量中，以相对值表征的肋排重量存在显著差异。与两齿周岁羊相比，乳齿羔羊的绝食失重更高、内脏器官占比更大，且肉色更浅。相较于饲喂玉米型日粮的试验个体，饲喂高浓缩高粱型日粮的舍饲育肥羔羊与周岁羊，其热、冷胴体率，肉色主观评分及肋排占比均更高。