Mendes A A, Watkins S E, England J A, Saleh E A, Waldroup A L, Waldroup P W
Department of Poultry Science, University of Arkansas, Fayetteville 72701, USA.
Poult Sci. 1997 Mar;76(3):472-81. doi: 10.1093/ps/76.3.472.
Four trials of identical experimental design were conducted to determine the effects of temperature, dietary Lys level, and dietary Arg:Lys ratios on performance and carcass yield of male broilers. Birds of a commercial strain were grown from 21 to 42 d of age in wire-floored finishing batteries placed in environmental chambers. The chambers were programmed to provide either a constant thermoneutral temperature (21.1 C), a constant cold temperature (15.5 C), or a cycling hot diurnal temperature (25.5 to 33.3 C). Within each environment there was a factorial arrangement of three Lys levels (1.0, 1.1, and 1.2%) with four Arg:Lys ratios (1.1:1, 1.2:1, 1.3:1, and 1.4:1). Environmental temperature significantly influenced virtually every characteristic examined. Hot cyclic temperatures reduced weight gain, feed intake, and breast meat yield, and increased feed conversion, dressing percentage, leg quarter yield, and abdominal fat content. The cold environment promoted increased feed intake and mortality. Ascites and cardiomyopathy were the leading causes of death under cold exposure and thermoneutral conditions, whereas complications arising from heat exposure were the main cause of death under hot cyclic conditions. Levels of Lys affected leg quarter yield and abdominal fat content over all environments but increased breast meat yield only under cold conditions. Increasing Arg:Lys ratios improved feed conversion and dressing percentage and reduced abdominal fat content; it could not be determined whether these responses were consistent with Arg per se or were due to a nonspecific N response. As increasing Lys levels or Arg:Lys ratios did not improve weight gain, increase breast meat yield, or attenuate adverse effects due to heat or cold exposure, it is concluded that the levels of Lys and Arg suggested for 21 to 42 d by the NRC are adequate for birds of this age under the environmental conditions encountered.
进行了四项实验设计相同的试验，以确定温度、日粮赖氨酸水平和日粮精氨酸:赖氨酸比例对雄性肉鸡生产性能和胴体产量的影响。选用商业品系的雏鸡，在置于环境舱内的金属网平养育肥笼中饲养，从21日龄养至42日龄。环境舱被设定为提供恒定的中性温度（21.1℃）、恒定的低温（15.5℃）或昼夜循环高温（25.5至33.3℃）。在每个环境条件下，设置了三个赖氨酸水平（1.0%、1.1%和1.2%）与四个精氨酸:赖氨酸比例（1.1:1、1.2:1、1.3:1和1.4:1）的析因安排。环境温度几乎显著影响了所检测的每一个特征。循环高温降低了体重增加、采食量和胸肉产量，并提高了饲料转化率、屠宰率、腿肉产量和腹部脂肪含量。寒冷环境促进了采食量增加和死亡率上升。腹水和心肌病是冷暴露和中性温度条件下的主要死亡原因，而热暴露引起的并发症是循环高温条件下的主要死亡原因。赖氨酸水平在所有环境条件下均影响腿肉产量和腹部脂肪含量，但仅在寒冷条件下提高了胸肉产量。提高精氨酸:赖氨酸比例改善了饲料转化率和屠宰率，并降低了腹部脂肪含量；无法确定这些反应是与精氨酸本身一致还是由于非特异性氮反应所致。由于增加赖氨酸水平或精氨酸:赖氨酸比例并未提高体重增加、增加胸肉产量或减轻热或冷暴露的不利影响，因此得出结论，在本环境条件下，美国国家研究委员会（NRC）建议的21至42日龄肉鸡的赖氨酸和精氨酸水平是足够的。
