Does environmental enrichment improve performance, morphometry, yield and weight of broiler parts at different ages?

ABSTRACT The inclusion of environmental enrichment in conventional broiler rearing can increase mobility, bone mass and muscle. This research aimed to evaluate the use of environmental enrichment in the rearing of broilers at different ages and its influence on performance, morphometry, yield and weight of the parts. It was used the completely randomized design in split-plot scheme, being the plots the treatments presence (T1) and absence (T2) of environmental enrichment and the subplots the broiler ages (1, 7, 14, 21, 28, 35 and 42 days), with 56 chicks in each treatment (T1 and T2). Data obtained were analyzed by the linear effect model of fixed effects and compared by Tukey’s test of means. The animals were raised in a controlled environment, divided into four boxes with dimensions: 1.5 × 1.0 × 0.7 m, containing rice straw bed. In T1 a ladder with a perch on top was used, distributed every 1.5 m2. Environmental enrichment used did not influence broiler’s zootechnical performance. Broilers’ morphometric properties, parts weight and body weight increased due to environmental enrichment and, improvement was observed in chicks rearing’s final phase. The environmental enrichment was beneficial for muscle and bone mass gain in the main commercial parts of the chicken carcass, in addition to reducing the allometric coefficient of the breasts in chickens.

摘要
在常规肉鸡养殖中添加环境富集（environmental enrichment）可提升肉鸡的活动能力、骨量与肌肉量。本研究旨在评估不同日龄肉鸡养殖中环境富集的应用效果，及其对肉鸡生产性能、形态学指标、屠宰部位产量与重量的影响。试验采用完全随机裂区设计，主区为环境富集添加组（T1）与不添加组（T2），副区为肉鸡日龄（1、7、14、21、28、35和42日龄），每个处理组（T1、T2）各配置56只雏鸡。采用固定效应线性模型对试验所得数据进行分析，并通过Tukey均值多重比较检验（Tukey’s test of means）进行组间差异比较。试验肉鸡在可控环境中饲养，饲养栏位分为4个规格为1.5×1.0×0.7米的单元，垫料采用稻草秸秆。T1组每1.5平方米设置1个带有顶部栖架的梯子作为环境富集设施。本次试验采用的环境富集设施未对肉鸡的畜牧生产性能产生显著影响。环境富集可提升肉鸡的形态学指标、屠宰部位重量与全身体重，且该改善效果在肉鸡饲养后期尤为显著。此外，环境富集可促进肉鸡主要商业屠宰部位的肌肉与骨量增长，同时降低鸡胸肉的异速生长系数。