Veldkamp T, Kwakkel R P, Ferket P R, Verstegen M W A
Animal Sciences Group, Wageningen UR, Edelhertweg 15, PO Box 65, 8200 AB Lelystad, The Netherlands.
Poult Sci. 2005 Feb;84(2):273-82. doi: 10.1093/ps/84.2.273.
The effects of ambient temperature (T; 18 vs. 28 degrees C), dietary energy level [E; 90, 100, and 110% of NRC (1994) recommendations], and dietary lysine level [LYS; 105 vs. 120% of NRC (1994) recommendations], and their interactions on feed intake, BW gain, feed:gain ratio, and carcass yields of male turkeys were studied from 29 to 140 d of age. The experiment was designed as a split plot, including T as the main plot and E and LYS as the subplot, with 60 pens containing 10 male turkeys each. Overall, feed intake, BW gain, and feed:gain ratio were significantly lower at high compared with low T. Feed intake decreased linearly as E increased and was more pronounced at low compared with high T. Metabolizable energy intake increased more at high compared with low T as E increased. Turkeys that were fed the highest E gained less weight until 84 d of age than those fed the lowest E. Dietary lysine was not the limiting amino acid because birds showed no response to extra lysine. Feed:gain decreased linearly as E level increased. Until 84 d of age, feed:gain decreased more at low compared with high T as E level increased. Breast meat yields were lower, and thigh, drum, and wing yields were higher at high than at low T. The highest E resulted in lower cold carcass yields, and breast meat yields, and higher thigh and drum yields than the lowest E. Dietary lysine level did not affect carcass yield. The results imply that when dietary lysine levels are adequate, dietary energy may be increased above NRC (1994) to improve feed efficiency, but some of the limiting amino acids after lysine may be increased in high-density diets to optimize breast meat yield. Particularly at high temperature in the period after 16 wk of age, dietary energy contents may be increased to at least 110% of NRC (1994) because turkeys will need more energy to dissipate heat.
研究了环境温度（T；18℃与28℃）、日粮能量水平[E；NRC（1994）推荐量的90%、100%和110%]、日粮赖氨酸水平[LYS；NRC（1994）推荐量的105%与120%]及其交互作用对29至140日龄雄性火鸡采食量、体重增加、料重比和胴体产率的影响。试验设计为裂区试验，以T为主区，E和LYS为副区，共有60个栏，每个栏含10只雄性火鸡。总体而言，与低温相比，高温下的采食量、体重增加和料重比显著更低。采食量随E增加呈线性下降，且在低温下比高温下更明显。随着E增加，与低温相比，高温下的可代谢能量摄入量增加更多。采食最高E水平日粮的火鸡在84日龄前比采食最低E水平日粮的火鸡增重更少。日粮赖氨酸不是限制性氨基酸，因为禽类对额外添加的赖氨酸无反应。料重比随E水平增加呈线性下降。在84日龄前，随着E水平增加，与高温相比，低温下料重比下降更多。高温下胸肉产率更低，大腿、小腿和翅膀产率更高。与最低E水平相比，最高E水平导致冷胴体产率和胸肉产率更低，大腿和小腿产率更高。日粮赖氨酸水平不影响胴体产率。结果表明，当日粮赖氨酸水平充足时，日粮能量可提高至高于NRC（1994）的水平以提高饲料效率，但在高密度日粮中，赖氨酸之后的一些限制性氨基酸可能需要增加以优化胸肉产率。特别是在16周龄后的高温期，日粮能量含量可提高至至少NRC（1994）推荐量的110%，因为火鸡需要更多能量来散热。
