Griffin D B, Savell J W, Morgan J B, Garrett R P, Cross H R
Department of Animal Science, Texas A&M University, College Station 77843-2471.
J Anim Sci. 1992 Aug;70(8):2411-30. doi: 10.2527/1992.7082411x.
One hundred beef carcasses were selected to represent the mix of cattle slaughtered across the United States. Selection criteria included breed type (60% British/continental European, 20% Bos indicus, and 20% dairy carcasses), sex class (beef and Bos indicus: 67% steers, 33% heifers; dairy: 100% steers), USDA quality grade (4% Prime, 53% Choice, and 43% Select), USDA yield grade (10% YG 1, 43% YG 2, 40% YG 3, and 7% YG 4), and carcass weight (steers: 272.2 to 385.6 kg, heifers: 226.8 to 340.2 kg). One side of each carcass was fabricated into boneless subprimals and minor cuts following Institutional Meat Purchase Specifications. After fabrication, subprimals were trimmed progressively of fat in .64-cm increments beginning with a maximum of 2.54 cm and ending with .64 cm. Linear regression models were developed for each individual cut, including fabrication byproduct items (bone, fat trim) to estimate the percentage yield of those cuts reported by USDA Market News. Strip loin, top sirloin butt, and gooseneck rounds from heifers tended to have a higher percentage yield at the same USDA yield grade than the same cuts from steers, possibly resulting from increased fat deposition on heifers. Percentage of fat trimmed from dairy steers was 2 to 3% lower than that from other sex-class/carcass types; however, due to increased percentage of bone and less muscle, dairy steers were lower-yielding. Fat trimmed from carcasses ranged from 7.9 to 15.6% as the maximum trim level decreased from 2.54 to .64 cm.
挑选了100具牛肉胴体来代表美国各地屠宰牛的混合情况。选择标准包括品种类型（60%英国/欧洲大陆品种、20%印度瘤牛和20%奶牛胴体）、性别类别（肉牛和印度瘤牛：67%阉牛、33%小母牛；奶牛：100%阉牛）、美国农业部质量等级（4%特级、53%精选级和43%合格级）、美国农业部产量等级（10%1级、43%2级、40%3级和7%4级）以及胴体重量（阉牛：272.2至385.6千克，小母牛：226.8至340.2千克）。按照机构肉类采购规范，将每具胴体的一侧加工成无骨肉块和小切块。加工后，肉块逐步以0.64厘米的增量修剪脂肪，起始最大厚度为2.54厘米，结束时为0.64厘米。针对每个单独切块建立线性回归模型，包括加工副产品项目（骨头、脂肪修剪物），以估算美国农业部市场新闻报道的这些切块的产率百分比。在相同的美国农业部产量等级下，小母牛的里脊、上腰部臀肉和颈肉切块的产率百分比往往高于阉牛的相同切块，这可能是由于小母牛脂肪沉积增加所致。奶牛阉牛修剪的脂肪百分比比其他性别类别/胴体类型低2%至3%；然而，由于骨头比例增加且肌肉较少，奶牛阉牛的产率较低。随着最大修剪厚度从2.54厘米降至0.64厘米，胴体修剪的脂肪比例在7.9%至15.6%之间。
