Department of Animal Production, Neiker-Tecnalia, Vitoria-Gasteiz, Spain.
Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Ås, Norway.
PLoS One. 2019 Apr 17;14(4):e0214070. doi: 10.1371/journal.pone.0214070. eCollection 2019.
To evaluate the utility of transect sampling for assessing animal welfare in large chicken flocks, we quantified relationships between environmental inputs, welfare problems detected using transect sampling, and production outcomes. We hypothesised that environmental inputs including environmental complexity (i.e. number of environmental enrichment types provided), space allowance, underfloor heating (presence or absence), and photoperiod regimen (18 h continuous vs 16 h intermittent) would correspond to variations in welfare assessment findings, which would predict production outcomes. We conducted on-farm welfare assessment of Norwegian broiler flocks at approximately 28 days of age. We sampled four transects (rows between feeder and drinker lines) per flock to determine litter quality and the proportions of chickens with compromised welfare as indicated by visual signs of walking difficulties, illness, skin wounds and small bird size. Production outcome measures included mortality, reasons for carcass rejection at slaughter, footpad dermatitis, growth rate, feed conversion and an integrated production index. Greater environmental complexity was associated with a reduction in skin wounds and total welfare problems on the farm, lower mortality, fewer rejections due to wounds and underweight birds, and fewer rejections overall. Higher space allowances within levels of environmental complexity were associated with fewer walking difficulties and welfare problems overall, a reduction in rejections due to wounds, and a higher growth rate and production index. Underfloor heating was associated with a reduction in rejections due to leg deformity, and intermittent light was associated with lower illness and skin wound rates on the farm, and lower mortality. Furthermore, fewer welfare problems and better litter quality on the farm were associated with fewer carcass rejections at slaughter. Thus, data from transect sampling varied with environmental inputs and production outcomes, supporting the validity of transect sampling for practical, animal-based on-farm welfare assessment.
为了评估在大型鸡群中使用横断抽样评估动物福利的效用，我们量化了环境投入、横断抽样检测到的福利问题以及生产结果之间的关系。我们假设，包括环境复杂性（即提供的环境丰富类型数量）、空间分配、地下加热（存在或不存在）和光照方案（18 小时连续与 16 小时间歇）在内的环境投入与福利评估结果的变化相对应，而这些结果将预测生产结果。我们在大约 28 日龄时对挪威肉鸡进行了农场福利评估。我们在每个鸡群中采样了四条横断线（在饲料线和饮水线之间的行），以确定垫料质量以及表现出行动困难、疾病、皮肤伤口和小鸟体型等视觉上的福利问题的鸡的比例。生产结果包括死亡率、屠宰时因尸体不合格而被拒收的原因、脚垫皮炎、生长速度、饲料转化率和综合生产指数。更高的环境复杂性与减少农场的皮肤伤口和总福利问题、降低死亡率、减少因伤口和体重不足而拒收的禽类以及总体上减少拒收有关。在环境复杂性水平内，更高的空间分配与整体行动困难和福利问题减少、因伤口而拒收的减少以及更高的生长速度和生产指数有关。地下加热与因腿部畸形而拒收的减少有关，间歇光照与农场内疾病和皮肤伤口发生率降低以及死亡率降低有关。此外，农场中福利问题和垫料质量的减少与屠宰时尸体拒收的减少有关。因此，横断抽样的数据因环境投入和生产结果而异，支持了横断抽样在实际的、基于动物的农场福利评估中的有效性。
