Rivera-Torres V, Noblet J, van Milgen J
Techna, BP10, Couëron, France.
Poult Sci. 2011 Jan;90(1):68-74. doi: 10.3382/ps.2010-00633.
In growing animals, requirements for many nutrients (and energy) are determined by the retention of these nutrients. During growth, this retention changes in an absolute way and also between nutrients and energy, resulting in changing nutrient requirements. The objective of this study was to describe the changes in chemical composition in male growing turkeys. The serial slaughter technique was used to determine the composition of amino acids, lipid, ash, and water in feather-free body (FFB) and feathers in male turkeys offered feed ad libitum from 1 to 15 wk of age. Allometric relations were used to describe changes in body composition. The feather content in the body decreased from 6% at 1 wk of age to less than 3% at 15 wk of age. The water and protein content in FFB decreased with increasing FFB mass, with allometric scalars (b) of, respectively, 0.967 and 0.970, whereas the lipid content increased with increasing FFB mass (b = 1.388). The water, protein, and ash content in fat-free FFB was constant and represented, respectively, 71.6, 24.2, and 4.2% of the fat-free FFB mass. The amino acid content of FFB protein was relatively constant and only the Cys content decreased between 1 and 15 wk of age, whereas the Ile content increased. Feathers were mostly composed of protein, and the protein content did not change during growth. During growth, the Lys, Met, Trp, His, Tyr, Asp, and Glu contents in feather protein decreased, whereas the Cys, Val, and Ser contents increased. The contribution of feathers to whole-body amino acid retention ranged from 5% for His to 33% for Cys. On average, the weight gain of FFB contained 21.3% protein and 12.7% lipid, corresponding to an energy content of 10.1 kJ/g. The weight gain of feathers contained 87.4% protein, corresponding to an energy content of 20.4 kJ/g. The results of the present study can be used in a factorial approach to determine nutrient requirements in growing turkeys.
在生长中的动物体内，许多营养素（以及能量）的需求量是由这些营养素的留存量决定的。在生长过程中，这种留存量会以绝对的方式发生变化，而且在营养素和能量之间也会有所不同，从而导致营养素需求的变化。本研究的目的是描述雄性生长火鸡化学成分的变化。采用连续屠宰技术来测定1至15周龄自由采食饲料的雄性火鸡无羽毛体（FFB）和羽毛中氨基酸、脂质、灰分和水分的组成。采用异速生长关系来描述身体组成的变化。火鸡体内羽毛含量从1周龄时的6%下降到15周龄时的不到3%。FFB中的水分和蛋白质含量随着FFB质量的增加而下降，异速生长标度（b）分别为0.967和0.970，而脂质含量则随着FFB质量的增加而增加（b = 1.388）。无脂肪FFB中的水分、蛋白质和灰分含量是恒定的，分别占无脂肪FFB质量的71.6%、24.2%和4.2%。FFB蛋白质中的氨基酸含量相对恒定，仅1至15周龄期间半胱氨酸含量下降，而异亮氨酸含量增加。羽毛主要由蛋白质组成，且生长过程中蛋白质含量不变。生长过程中，羽毛蛋白质中的赖氨酸、蛋氨酸、色氨酸、组氨酸、酪氨酸、天冬氨酸和谷氨酸含量下降，而半胱氨酸、缬氨酸和丝氨酸含量增加。羽毛对全身氨基酸留存的贡献范围从组氨酸的5%到半胱氨酸的33%。平均而言，FFB的体重增加中含有21.3%的蛋白质和12.7% 的脂质，能量含量为10.1 kJ/g。羽毛的体重增加中含有87.4%的蛋白质，能量含量为20.4 kJ/g。本研究结果可用于析因法来确定生长中火鸡的营养需求。
