Lewis P D, Perry G C, Farmer L J, Patterson R L
Department of Clinical Veterinary Science, University of Bristol, Langford, Bristol BS18 7DU, UK.
Meat Sci. 1997 Apr;45(4):501-16. doi: 10.1016/s0309-1740(96)00084-8.
'Label Rouge' (LR) chickens are reputed to possess improved sensory characteristics compared with birds reared under intensive conditions. The effects on body weight, food utilisation, behaviour and carcass composition, of genotype (Ross I vs ISA '657'), diet (conventional UK broiler vs LR) and stocking density (17.0 birds m(-2),vs 4.25 birds m(-2)) were evaluated in a 2 × 2 × 2 experiment. ISA birds were grown to 83 days, and compared with Ross birds grown to 48 days; additionally ad libitum and control-fed Ross birds were grown to 83 days. Performance and behaviour parameters were assessed empirically. The effects on carcass composition were evaluated using standardised carcass dissection techniques and analysed by analysis of variance. ISA birds grown under LR conditions to 83 days had similar body weights to Ross birds grown under UK broiler conditions to 48 days, but LR birds consumed more food, and converted food into meat less efficiently. LR birds had no mortality, whilst UK broiler mortality was 11.3%. Under similar conditions, Ross birds had a faster body weight gain, a larger food intake, but more efficient food conversion ratio and higher incidence of mortality. Birds stocked 17.0 m(-2) had lower body weights, consumed less food and, when fed UK diets, converted food less efficiently than birds stocked 4.25 m(-2). Both genotypes had a faster growth rate on UK diets, similar food intakes, and, as a result, better food conversion than birds given LR diets. LR and UK broiler birds had similar carcass component weights, breast meat yields, and total meat yield, but LR birds had less meat on the frame, larger drumsticks and more meat on the wings. Under similar conditions, ISA birds had a larger percentage of wing and total bone, but a smaller percentage of breast meat and total meat yields. When Ross birds had controlled growth, total meat, bone and skin yields were similar to those of ISA birds. Birds stocked 4.25 m(-2) had more breast meat and larger frames than, but similar meat, bone and skin yields to, birds stocked 17.0 m(-2). Most carcass components were heavier in birds fed UK broiler diets, but, on a percentage basis, these birds had larger thighs, but smaller drumsticks.
“红标签”（LR）鸡据称与在集约化条件下饲养的鸡相比具有更好的感官特性。在一项2×2×2实验中，评估了基因型（罗斯I型与ISA '657'）、日粮（英国传统肉鸡日粮与LR日粮）和饲养密度（17.0只/平方米对4.25只/平方米）对体重、食物利用率、行为和胴体组成的影响。ISA鸡饲养至83天，并与饲养至48天的罗斯鸡进行比较；此外，自由采食和限饲的罗斯鸡饲养至83天。通过实证评估性能和行为参数。使用标准化的胴体解剖技术评估对胴体组成的影响，并通过方差分析进行分析。在LR条件下饲养至83天的ISA鸡体重与在英国肉鸡条件下饲养至48天的罗斯鸡相似，但LR鸡消耗更多食物，且将食物转化为肉的效率较低。LR鸡无死亡情况，而英国肉鸡死亡率为11.3%。在相似条件下，罗斯鸡体重增加更快，采食量更大，但食物转化率更高且死亡率更高。饲养密度为17.0只/平方米的鸡体重较低，消耗食物较少，且在饲喂英国日粮时，其食物转化率低于饲养密度为4.25只/平方米的鸡。两种基因型在英国日粮上生长速度更快，采食量相似，因此食物转化率比饲喂LR日粮的鸡更好。LR鸡和英国肉鸡的胴体各部分重量、胸肉产量和总肉产量相似，但LR鸡的胴体上肉较少，鸡腿较大，翅膀上肉较多。在相似条件下，ISA鸡翅膀和总骨的比例较大，但胸肉和总肉产量的比例较小。当罗斯鸡生长受到控制时，其总肉、骨和皮产量与ISA鸡相似。饲养密度为4.25只/平方米的鸡比饲养密度为17.0只/平方米的鸡胸肉更多、骨架更大，但肉、骨和皮产量相似。大多数胴体部分在饲喂英国肉鸡日粮的鸡中更重，但按百分比计算，这些鸡大腿更大，鸡腿更小。
