Epidemiology, Health and Welfare Unit, Ploufragan-Plouzané-Niort Laboratory, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Ploufragan, France.
Technical Institute for Poultry (ITAVI), 37380 Nouzilly, France.
Poult Sci. 2024 Sep;103(9):103993. doi: 10.1016/j.psj.2024.103993. Epub 2024 Jun 27.
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.
传统的肉鸡生产需要朝着更适合动物的生产系统发展，以满足消费者对动物福利日益增长的关注。遗传和饲养密度是实现这一转变的两个最有希望的线索。在这项研究中，6 个生长速度不同（42-61g/d）的品系在不同的密度下饲养：37kg/m²（高密度）和 29kg/m²（低密度）。在相同的体重 1.80-1.95kg 时，我们评估了生长速度和饲养密度如何影响肉鸡的行为（一般活动、与丰容的相互作用）、肉鸡的健康（死亡率、腿部问题、清洁度和羽毛生长）和垫料质量。密度不影响体重、死亡率或行为。对于所有的品系，低密度与跗关节烧伤的发生率较低、步态评分较好、垫料质量和肉鸡清洁度提高有关。对于 3 个受跗关节皮炎影响最大的品系，低密度鸡舍的发生率低于高密度鸡舍。当生长速度低于对照品系（罗斯 308）时，活动减少的鸟类较少，站立和与丰容互动（如实验中所建议的）的鸟类更多。其他福利指标，如步态评分、羽毛生长也有所改善。随着生长速度的增加，垫料湿度降低，有助于改善腿部状况和保持胸部清洁。跗关节烧伤的发生率和某些行为（即，啄食或行走/奔跑的鸟类比例）不受生长速度的影响。生长速度较慢时，觅食的鸟类比例较高。这些结果表明，作为初步措施降低生长速度，并作为补充措施降低密度，将提高传统肉鸡的福利。
