Energy partitioning by broiler breeder hens in conventional daily-restricted feeding and precision feeding systems.

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