Cahaner A, Pinchasov Y, Nir I, Nitsan Z
Department of Genetics, Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot, Israel.
Poult Sci. 1995 Jun;74(6):968-75. doi: 10.3382/ps.0740968.
The effect of dietary protein on growth, feed intake and efficiency, abdominal fat deposition, and breast meat yield was investigated in broiler males from a commercial stock (WI) and from experimental stocks selected for low (LF) or high (HF) abdominal fat. All birds were kept at constant high ambient temperature (32 C) and were provided with low- (LP) or high-protein (HP) diets from hatch until 8 wk of age (Experiment 1) or from 4 to 8 wk of age (Experiment 2). In both experiments, HP diet significantly increased 4- to 8-wk BW gain in the LF and HF stocks but reduced it in the WI stock as compared with the LP diet. Abdominal fat, as percentage of BW, was almost twofold higher in the HF birds than in the LF ones, with WI mean being intermediate. In contrast to the HF and WI birds, in which abdominal fat decreased with increased protein intake, abdominal fat was not affected by dietary protein in the LF stock. The HP diet substantially increased breast meat yield in LF birds but not in the WI birds, with HF birds exhibiting intermediate increase in breast meat weight. It was concluded that birds of varied inherent growth rate and tendencies toward protein and fat deposition respond differently to dietary protein level under heat stress.
研究了日粮蛋白质对来自商业种群（WI）以及为低腹脂（LF）或高腹脂（HF）选育的实验种群的雄性肉鸡生长、采食量和效率、腹部脂肪沉积及胸肉产量的影响。所有鸡只均饲养在恒定的高温环境（32℃）下，从出雏至8周龄（实验1）或从4至8周龄（实验2）分别饲喂低蛋白（LP）或高蛋白（HP）日粮。在两个实验中，与LP日粮相比，HP日粮显著提高了LF和HF种群4至8周龄的体重增加，但降低了WI种群的体重增加。以体重百分比计，HF鸡的腹部脂肪几乎是LF鸡的两倍，WI鸡的均值介于两者之间。与HF和WI鸡不同，LF种群中腹部脂肪不受日粮蛋白质影响，而HF和WI鸡的腹部脂肪随蛋白质摄入量增加而减少。HP日粮显著提高了LF鸡的胸肉产量，但对WI鸡没有影响，HF鸡胸肉重量增加介于两者之间。得出的结论是，在热应激条件下，具有不同固有生长速率以及蛋白质和脂肪沉积倾向的鸡只对日粮蛋白质水平的反应不同。
