Andersen M K, Field R A, Riley M L, Crouse J D, Bailey D G
Anim. Sci. Dept., University of Wyoming, Laramie 82071.
J Anim Sci. 1991 Dec;69(12):4690-5. doi: 10.2527/1991.69124690x.
Forty-eight Suffolk x white-faced ram and wether lambs approximately 5, 7, or 9 mo of age were slaughtered to evaluate the effects of age and gender on difficulty of pelt removal, pelt damage, and leg damage. A commercial belt-type pelt puller and a scale that recorded force required to remove the pelt from the thickest part of the legs was used as lambs hung suspended from their front legs. Rams required more force (P less than .05) to remove the pelt than wethers, and the difference between genders became larger as age increased. Neither pelt damage due to grain crack nor leg damage judged by amount of fell and fat removed by the pelt puller changed with age. Rams possessed thicker pelts (P less than .05) than wethers; this plus a greater amount of collagen crosslinking in ram skins could be responsible for the slightly smaller amount of grain crack observed in ram pelts. Factors involved in difficulty of pelt removal in ram lambs included age, splenius weight, and overall maturity. Difficulty of pelt removal in wether lambs was best predicted by including age and splenius weight in the model. These data tend to support packers' common practice of discounting rams over 5 mo of age because rams develop masculine characteristics and become harder to dress with increasing age.
选取了48只萨福克与白面杂交的公羔和羯羔，年龄约为5、7或9月龄，屠宰以评估年龄和性别对剥皮难度、皮张损伤和腿部损伤的影响。当羔羊从前腿悬挂吊起时，使用商用皮带式剥皮机和一个记录从腿部最厚处剥下皮张所需力的秤。公羊剥皮所需的力比羯羊更大（P小于0.05），且随着年龄增长，两性之间的差异变得更大。因粒面裂纹导致的皮张损伤以及根据剥皮机去除的毛和脂肪量判断的腿部损伤均不随年龄变化。公羊的皮张比羯羊更厚（P小于0.05）；这一点加上公羊皮肤中更多的胶原交联可能是公羊皮张中观察到的粒面裂纹略少的原因。影响公羊羔剥皮难度的因素包括年龄、夹肌重量和整体成熟度。在模型中纳入年龄和夹肌重量能最好地预测羯羊羔的剥皮难度。这些数据倾向于支持加工厂对5月龄以上公羊打折的常见做法，因为随着年龄增长，公羊会发育出雄性特征，变得更难进行屠宰加工。
