Welfare indicators for laying Japanese quails caged at different densities

Abstract In the way to reduce costs in the poultry production, high densities of birds are adopted in the production systems. Such high densities can lead to an inappropriate environment, compromising the welfare and decreasing the animal performance. In this work we aimed to evaluate the effects of different densities on the productive yield, egg quality and immunological aspects of Japanese quails. It was used 816 Japanese quails, during egg production phase, in a random design, with four treatments (121.43 cm2/bird; 106.25 cm2/bird; 94.44 cm2/bird and 85.00 cm2/bird) with six repetitions each. Results indicate density did not interfere on egg quality and all treatments can be considered excellent, once the Haugh Unit was 88.03. Therefore, higher densities decline the yield, decreasing the eggs weight (10.35 g), the laying percentage (88%), egg mass (9.16 g) and the week average feed consumption (157.35 g). IgY values were higher at smaller cage density, suggesting birds in this condition presented better immunological condition, related to welfare and stress factors, all linked to immunoglobulins IgY.

摘要：为降低家禽养殖成本，生产系统中普遍采用高密度饲养模式，但此类高密度饲养会导致饲养环境失宜，损害家禽福利并降低其生产性能。本研究旨在评估不同饲养密度对产蛋期日本鹌鹑产蛋性能、蛋品质及免疫状态的影响。试验选用816只产蛋期日本鹌鹑，采用完全随机试验设计，设置4个饲养密度处理组（分别为121.43 cm²/只、106.25 cm²/只、94.44 cm²/只及85.00 cm²/只），每组设置6个重复。试验结果表明，饲养密度未对蛋品质产生显著影响：所有处理组的哈氏单位（Haugh Unit）均值达88.03，蛋品质均属优异水平；而高密度饲养则会降低生产性能，具体表现为蛋重降至10.35 g、产蛋率为88%、蛋总重为9.16 g，同时周均采食量降至157.35 g。此外，低笼养密度组的免疫球蛋白Y（IgY）水平更高，表明该饲养条件下的鹌鹑具有更优的免疫状态，这与福利及应激因素密切相关，此类免疫状态均与免疫球蛋白IgY直接关联。