An empirical linear mixed model was derived to describe metabolizable energy (ME) partitioning in broiler breeder hens. Its coefficients described ME used for total heat production (HP), growth (ADG), and egg mass (EM). A total of 480 Ross 308 hens were randomly and equally assigned to 2 treatments: precision feeding (PF) and conventional daily-restricted feeding (CON) from 23 to 34 wk of age. The PF system allowed birds to enter feeding stations voluntarily at any time, weighed them, and provided access to feed for 60 s if their BW was less than the breeder-recommended target BW. The CON birds were fed daily each morning. Energetic efficiency of hens was evaluated using residual feed intake (RFI), defined as the difference between observed and predicted ME intake (MEI). The energy partitioning model predicted (P < 0.05): MEI = A × BW0.67 + 1.75 × ADG + 0.75 × EM + ϵ. The coefficient A, a vector of age-specific HP, was 142 kcal/kg0.67/d; the energy requirement for growth and EM was 1.75 and 0.75 kcal/g, respectively. For the CON and the PF hens, respectively, MEI was 366 and 354 kcal/d (P = 0.006); RFI was -5.9 and 6.7 kcal/d (P = 0.009); HP% was 85.5 and 87.7 (P < 0.001); hen-day egg production (HDEP) was 65.5 and 55.2% (P < 0.001). Although the CON hens had higher MEI, the model predicted lower HP%; thus, CON hens had more nutrients available for egg production, increased egg production, and were more energetically efficient than the PF hens. The decreased egg production by the PF hens was likely due to these hens receiving production-related feed increases after an egg was laid. However, feed allocation increases for the CON hens resulted in increasing MEI for all CON hens at the same time. Therefore, the PF hens had lower MEI and lower HDEP than the CON hens.

中文翻译：

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肉种鸡在常规日限饲和精准饲喂系统中的能量分配。

导出了一个经验线性混合模型来描述肉种鸡的代谢能 (ME) 分配。它的系数描述了用于总产热 (HP)、生长 (ADG) 和卵量 (EM) 的 ME。总共 480 只罗斯 308 母鸡被随机平均分配到 2 个处理组：精确饲喂 (PF) 和 23 至 34 周龄的常规每日限制饲喂 (CON)。PF 系统允许鸡只在任何时候自愿进入饲喂站，称重，如果体重低于饲养员推荐的目标体重，可以在 60 秒内提供饲料。每天早上喂食CON鸟。使用剩余采食量 (RFI) 评估母鸡的能量效率，定义为观察到的和预测的 ME 采食量 (MEI) 之间的差异。能量分配模型预测（P < 0.05）：MEI = A × BW0.67 + 1。75 × ADG + 0.75 × EM + ε。系数 A 是年龄特异性 HP 的向量，为 142 kcal/kg0.67/d；生长和 EM 的能量需求分别为 1.75 和 0.75 kcal/g。对于 CON 和 PF 母鸡，MEI 分别为 366 和 354 kcal/d (P = 0.006)；RFI 为 -5.9 和 6.7 kcal/d (P = 0.009)；HP% 分别为 85.5 和 87.7 (P < 0.001)；母鸡日产蛋量 (HDEP) 分别为 65.5 和 55.2% (P < 0.001)。虽然 CON 母鸡的 MEI 较高，但该模型预测的 HP% 较低；因此，CON 母鸡比 PF 母鸡有更多的养分可用于产蛋，增加产蛋量，并且能量效率更高。PF 母鸡产蛋量减少可能是由于这些母鸡在产蛋后接受了与生产相关的饲料增加。然而，CON 母鸡的饲料分配增加导致所有 CON 母鸡的 MEI 同时增加。因此，PF 母鸡的 MEI 和 HDEP 低于 CON 母鸡。