Anderson D C, Kress D D, Burfening P J, Blackwell R L
J Anim Sci. 1986 Apr;62(4):950-7. doi: 10.2527/jas1986.624950x.
Feedlot and carcass characteristics of 276 steers from five closed lines of Hereford cattle and reciprocal crosses among these lines were studied. The traits studied were initial weight, final weight, 224-d gain, days on test, hot carcass weight, marbling score, longissimus muscle area, fat thickness, yield grade, dressing percentage and shear force. Year of record was a significant source of variation for most traits. Age of dam was a significant source of variation for growth traits but not carcass traits. Line of sire affected initial weight, final weight, 224-d gain, days on test, marbling score and dressing percentage. Significant heterosis was observed only for hot carcass weight. Heterosis estimates were 1.9% for initial weight, 2.2% for final weight, 2.5% for 224-d gain, -2.1% for days on test, .6% for hot carcass weight, -.6% for marbling score, 0 for carcass grade, .6% for longissimus muscle area, 2.3% for backfat thickness, .9% for yield grade, -.9% for dressing percent and -10.9% for shear force. Initial age on test affected only hot carcass weight. Hot carcass weight, dressing percentage, marbling score, longissimus muscle area and fat thickness were affected by slaughter weight. Slaughter age affected dressing percent and marbling score.
对来自五个赫里福德牛封闭品系的276头阉牛及其品系间正反交后代的饲养场和胴体特征进行了研究。所研究的性状包括初始体重、最终体重、224天增重、试验天数、热胴体重、大理石花纹评分、背最长肌面积、脂肪厚度、产肉等级、屠宰率和剪切力。记录年份是大多数性状变异的一个重要来源。母牛年龄是生长性状变异的一个重要来源，但不是胴体性状变异的来源。父本品系影响初始体重、最终体重、224天增重、试验天数、大理石花纹评分和屠宰率。仅在热胴体重方面观察到显著的杂种优势。初始体重的杂种优势估计值为1.9%，最终体重为2.2%，224天增重为2.5%，试验天数为-2.1%，热胴体重为0.6%，大理石花纹评分为-0.6%，胴体等级为0，背最长肌面积为0.6%，背膘厚度为2.3%，产肉等级为0.9%，屠宰率为-0.9%，剪切力为-10.9%。试验初始年龄仅影响热胴体重。热胴体重、屠宰率、大理石花纹评分、背最长肌面积和脂肪厚度受屠宰体重的影响。屠宰年龄影响屠宰率和大理石花纹评分。
