Camfield P K, Brown A H, Lewis P K, Rakes L Y, Johnson Z B
Department of Animal Science, University of Arkansas, Fayetteville 72701, USA.
J Anim Sci. 1997 Jul;75(7):1837-44. doi: 10.2527/1997.7571837x.
Weaned British x continental crossbred steers (n = 108, 7 to 8 mo of age) of medium or large frame were used in a replicated experiment with a 2 x 4 factorial arrangement of treatments over 2 yr. Management regimens consisted of backgrounding for 150 d and finishing for 0, 30, 60, and 90 d. Carcass data were collected, and samples from the longissimus muscle were analyzed for long-chain fatty acids, cholesterol, and the percentage of fat. Duration of finishing was a source of variation for hot carcass weight, marbling, percentage of kidney, pelvic, and heart fat, fat thickness, yield and quality grades, cooking loss, flavor intensity, and stearic, oleic, and linolenic acids (P < .05). Myristic, palmitic, and margaric acids were negatively correlated (P < .05) with juiciness and with "cowy" and "painty" taste characteristics. Frame score did not influence long-chain fatty acids; however, there was a relationship between long-chain fatty acids and management regimen. Results suggest that feeding steers a finishing diet up to 90 d after backgrounding for 150 d has a positive influence on carcass characteristics without affecting cholesterol.
选用中等或大框架的断奶英国×大陆杂交阉牛（n = 108，7至8月龄），在一项重复试验中，采用2×4析因处理安排，试验持续2年。管理方案包括150天的育肥前期和0、30、60和90天的育肥后期。收集胴体数据，并对背最长肌样本进行长链脂肪酸、胆固醇和脂肪百分比分析。育肥后期的时长是热胴体重、大理石花纹、肾、骨盆和心脏脂肪百分比、脂肪厚度、产量和质量等级、烹饪损失、风味强度以及硬脂酸、油酸和亚麻酸的变异来源（P < 0.05）。肉豆蔻酸、棕榈酸和十七烷酸与多汁性以及“牛膻味”和“油漆味”的味道特征呈负相关（P < 0.05）。框架评分不影响长链脂肪酸；然而，长链脂肪酸与管理方案之间存在关联。结果表明，在150天育肥前期后给阉牛饲喂长达90天的育肥后期日粮，对胴体特征有积极影响，且不影响胆固醇含量。
