Understanding energy partitioning in broiler breeders is needed to provide efficiency indicators for breeding purposes. This study compared 4 nonlinear models partitioning metabolizable energy (ME) intake to BW, average daily gain (ADG), and egg mass (EM) and described the effect of BW and rearing photoperiod on energy partitioning. Ross 708 broiler breeders (n = 180) were kept in 6 pens, controlling individual BW of free run birds with precision feeding stations. Half of the birds in each chamber were assigned to the breeder-recommended target BW curve (Standard) or to an accelerated target BW curve reaching the 21-week BW at week 18 (High). Pairs of chambers were randomly assigned to 8L:16D, 10L:14D, or 12L:12D rearing photoschedules and photostimulated with 16L:8D at week 21. Model [I] was: MEId = a × BWb + c × ADG × BWd + e × EM + ε, where MEId = daily ME intake (kcal/day); BW in kg; ADG in g/day; EM in g/day. Models [II-IV] were nonlinear mixed versions of model [I] and included individual [II], age-related [III], or both individual and age-related [IV] random terms to explain these sources of variation in maintenance requirement (a). Differences were reported as significant at P ≤ 0.05. The mean square error was 2,111, 1,532, 1,668, and 46 for models [I-IV] respectively, inferring extra random variation was explained by incorporating 1 or 2 random terms. Estimated ME partitioned to maintenance [IV] was 130.6 ± 1.15 kcal/kg0.58, and the ME requirement for ADG and EM were 0.63 ± 0.03 kcal/g/kg0.54 and 2.42 ± 0.04 kcal/g, respectively. During the laying period, maintenance estimates were 124.2 and 137.4 kcal/kg0.58 for standard and high BW treatment, and 130.7, 132.2, and 129.5 kcal/kg0.58 for the 8L:16D, 10L:14D, or 12L:12D treatments, respectively. Although hens on the standard BW treatment with a 12L:12D rearing photoschedule were most energetically conservative, their reproductive performance was the poorest. Model IV provided a new biologically sound method for estimation of life-time energy partitioning in broiler breeders including an age-related random term.

中文翻译：

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模拟体重和饲养光周期不同的肉种鸡的终生能量分配。

需要了解肉鸡育种者的能量分配，以提供育种目的的效率指标。这项研究比较了4种将可代谢能量（ME）摄入量分配给体重，平均日增重（ADG）和蛋重（EM）的非线性模型，并描述了体重和饲养光周期对能量分配的影响。将罗斯708肉鸡育种家（n = 180）放在6只围栏中，用精确的饲喂站控制自由奔跑的家禽的个体体重。每个鸡舍中有一半的家禽被指定为饲养员推荐的目标体重曲线（标准）或加速的目标体重曲线，在第18周达到21周体重（高）。成对的室被随机分配到8L：16D，10L：14D或12L：12D的饲养日程中，并在第21周用16L：8D进行光刺激。模型[I]为：MEId = a×BWb + c×ADG×BWd + e ×EM +ε，其中MEId =每日ME摄入量（千卡/天）；体重千克 ADG（克/天）；EM（克/天）。模型[II-IV]是模型[I]的非线性混合版本，其中包括个体[II]，与年龄相关的[III]或个体与年龄相关的[IV]随机术语，以解释维护需求变化的这些来源（一种）。据报道，在P≤0.05时差异显着。模型[I-IV]的均方误差分别为2,111、1,532、1,668和46，可以通过合并1个或2个随机项来解释额外的随机变化。分配给维护[IV]的估计ME值为130.6±1.15 kcal / kg0.58，ADG和EM的ME需求分别为0.63±0.03 kcal / g / kg0.54和2.42±0.04 kcal / g。在产蛋期间，标准体重和高体重体重的维持率分别为124.2和137.4 kcal / kg0.58，以及130.7、132.2和129。对于8L：16D，10L：14D或12L：12D处理，分别为5 kcal / kg0.58。尽管采用12L：12D饲养日程的标准BW处理的母鸡在能量上最保守，但其繁殖性能最差。模型IV提供了一种新的生物合理的方法，用于评估肉鸡育种者的终生能量分配，包括与年龄有关的随机术语。