PDF(Pubmed)
Abstract：
Conventional broiler production needs to evolve towards more animal-friendly production systems in order to meet increasing consumer concerns regarding animal welfare. Genetics and stocking density are 2 of the most promising leads to make this change possible. In this study, 6 strains with different growth rates (42-61 g/d) were reared at contrasting densities: 37 kg/m² (HD) and 29 kg/m² (LD). At the same body weight of 1.80-1.95 kg, we evaluated how growth rate and stocking density influenced broiler behaviors (general activity, interactions with enrichments), broiler health (mortality, leg problems, cleanliness and plumage growth) and litter quality. Density did not affect body weight, mortality or behaviors. For all strains, LD was associated with a lower prevalence of hock burns, a better gait score, and improved litter quality and broiler cleanliness. For the 3 strains most affected by pododermatitis, a lower prevalence was observed in LD than in HD pens. Fewer birds were inactive and more birds were standing and interacting with the enrichments (as proposed in the experiment) as soon as the growth rate was lower than that of the control strain (Ross 308). Others welfare indicators such as gait score, plumage growth improved as well. Litter humidity decreased with growth rate, contributing to better leg conditions and cleaner breasts. The prevalence of hock burns and certain behaviors (i.e., the proportion of birds grooming or walking/running) were not affected by growth rate. The proportion of birds foraging was higher at a lower growth rate. These results suggest that reducing growth rate as a preliminary measure, and reducing density as a supplementary one, would improve conventional broiler welfare.
摘要：
传统的肉鸡生产需要向更加动物友好的生产系统发展，以满足消费者对动物福利的日益关注。遗传和放养密度是使这种变化成为可能的最有希望的2条。在这项研究中,在对比密度下饲养了6个具有不同生长速率（42-61g/d）的菌株：37kg/m²（HD）和29kg/m²（LD）。在1.80-1.95公斤的相同体重下，我们评估了生长速度和放养密度如何影响肉鸡行为(一般活动，与丰富的互动)，肉鸡健康(死亡率，腿部问题,清洁度和羽毛生长）和凋落物质量。密度不影响体重，死亡率或行为。对于所有菌株，LD与较低的烫伤患病率相关，更好的步态分数,提高了垃圾质量和肉鸡清洁度。对于受足皮炎影响最大的3种菌株，LD的患病率低于HD笔.一旦生长速率低于对照品系的生长速率(Ross308),就会有较少的鸟类不活动,并且有更多的鸟类站立并与富集物相互作用(如实验中提出的)。其他福利指标，如步态得分，羽毛生长也有所改善。凋落物湿度随生长速率降低,有助于更好的腿部状况和更清洁的乳房。烫伤的患病率和某些行为(即，鸟类修饰或步行/跑步的比例）不受生长速度的影响。在较低的增长率下，鸟类觅食的比例较高。这些结果表明，降低增长率作为一项初步措施，减少密度作为补充，将提高传统的肉鸡福利。
