Brickett K E, Dahiya J P, Classen H L, Gomis S
Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada, S7N 5A8.
Poult Sci. 2007 Oct;86(10):2172-81. doi: 10.1093/ps/86.10.2172.
The objective of this study was to examine main and interactive effects of nutrient density (ND), feed form (FF; mash, pellet), and lighting program (12L:12D, 20L:4D) on production characteristics and meat yield of broilers raised to 35 d of age. Diets (starter, grower, and finisher) were formulated so that amino acid levels were in proportion to the dietary energy level. Lighting programs were initiated at 4 d of age. Body weight was not affected by ND when diets were fed in a pellet form but decreased in a linear manner with lower ND when fed as a mash. Final BW of birds fed mash were less than those of birds fed pellet diets. Feed to gain ratio decreased with increasing ND but was not affected by FF. Feed intake decreased with increasing ND and was lower for birds fed mash. The effect of ND on feed intake was less when birds were fed mash in contrast to pellet diets (P(ND x F) < 0.0001). Dietary ND had no effect on mortality, but feeding mash decreased mortality (3.8%) compared with feeding pelleted feed (5.6%). Lighting programs affected production characteristics independently of ND and FF. Use of 12L:12D reduced BW, feed to gain ratio, feed intake, and mortality compared with 20L:4D. Similarly, carcass components were not affected by ND when fed in pellet form but decreased with lower ND when fed as a mash. Overall, carcass yields were reduced when broilers were fed mash or provided with 12L:12D. Female birds had higher carcass yields and increased proportional breast meat deposition compared with males.
本研究的目的是考察营养密度（ND）、饲料形态（FF；粉料、颗粒料）和光照程序（12小时光照：12小时黑暗、20小时光照：4小时黑暗）对饲养至35日龄肉鸡的生产性能和产肉量的主要及交互作用。日粮（开食料、生长料和育肥料）的配方设计使得氨基酸水平与日粮能量水平成比例。光照程序在4日龄开始实施。日粮以颗粒料形式饲喂时，体重不受营养密度的影响，但以粉料形式饲喂时，体重随营养密度降低呈线性下降。饲喂粉料的鸡的最终体重低于饲喂颗粒料日粮的鸡。料重比随营养密度的增加而降低，但不受饲料形态的影响。采食量随营养密度的增加而降低，饲喂粉料的鸡的采食量更低。与颗粒料日粮相比，以粉料形式饲喂时，营养密度对采食量的影响较小（P（营养密度×饲料形态）<0.0001）。日粮营养密度对死亡率无影响，但与饲喂颗粒料（5.6%）相比，饲喂粉料可降低死亡率（3.8%）。光照程序独立于营养密度和饲料形态影响生产性能。与20小时光照：4小时黑暗相比，采用12小时光照：12小时黑暗可降低体重、料重比、采食量和死亡率。同样，日粮以颗粒料形式饲喂时，胴体组成不受营养密度的影响，但以粉料形式饲喂时，胴体组成随营养密度降低而减少。总体而言，肉鸡饲喂粉料或采用12小时光照：12小时黑暗时，胴体产量降低。与雄性相比，雌性鸡的胴体产量更高，胸肉沉积比例增加。
