Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5A8.
Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5A8.
Poult Sci. 2022 Jul;101(7):101956. doi: 10.1016/j.psj.2022.101956. Epub 2022 May 6.
Nicholas Select hens (n = 3,550 poults in each of 2 experimental trials) were randomly placed in 1 of 4 stocking density (SD) treatments of 30, 40, 50, or 60 kg/m until 11 wk. Birds were housed in open rooms (67.5 m) with 4 replications per treatment. Ventilation was adjusted in each room independently to ensure air quality measures did not differ across replicate rooms. At wk 8 and 11, footpad lesions, mobility, feather cover and cleanliness, behavior (recorded), and litter moisture were evaluated. Incidences of aggressive pecking were recorded daily. Heterophil/lymphocyte (H/L) ratios were evaluated at 3, 5, 8, and 11 wk. Data were analyzed using regression analyses in SAS 9.4 (Proc Reg and Proc RSReg; SD as independent variable). Differences were considered significant when P ≤ 0.05. Gait scores were not affected by SD. Average footpad scores worsened with increasing SD at wk 8 (linear) but were not affected at wk 11. Total feather cover scores and average feather cleanliness were poorer at high SD (linear) at wk 8 and 11. The incidence of aggressive pecking and culls for aggressive damage decreased linearly as SD increased. At 5 (linear) and 11 (quadratic) wk, H/L ratios increased as SD increased. At 8 wk, H/L ratios were highest in the 40 kg/m treatment (quadratic). At 8 wk, the percentage of birds at the feeder, resting, and total disturbances linearly increased as SD increased. The percentage of birds standing, walking, and litter pecking decreased linearly with increasing SD, while total aggressive behaviors (sum of fighting and aggressive pecking) decreased (quadratic). At 11 wk, the percentage of birds at the drinker, and decreased with increasing SD while resting, feather pecking, and severe disturbances increased as SD increased. Litter moisture increased linearly with increasing SD (wk 11). Turkey hen health and welfare were negatively impacted by higher SD. At low SD, there was notably more aggression which may also impact welfare.
尼古拉斯选择了 3550 只母鸡（每个实验试验中 30、40、50 或 60 公斤/米的 2 个处理组各有 3550 只小鸡），直到 11 周，将其随机放置在 4 个饲养密度（SD）处理组中的 1 个中。鸡群饲养在开放式房间（67.5 米）中，每个处理组有 4 个重复。每个房间的通风都进行了独立调整，以确保不同重复房间的空气质量措施不会有所不同。在第 8 和 11 周，评估了脚垫病变、移动性、羽毛覆盖率和清洁度、行为（记录）以及垫料湿度。每天记录攻击啄的发生率。在第 3、5、8 和 11 周评估嗜中性粒细胞/淋巴细胞（H/L）比值。使用 SAS 9.4 中的回归分析（Proc Reg 和 Proc RSReg；SD 作为独立变量）分析数据。当 P ≤ 0.05 时，认为差异具有统计学意义。步态评分不受 SD 的影响。在第 8 周，随着 SD 的增加，平均脚垫评分逐渐恶化（线性），但在第 11 周没有影响。在第 8 和 11 周，高 SD 时的总羽毛覆盖率和平均羽毛清洁度较差（线性）。随着 SD 的增加，攻击性啄和因攻击性损伤而淘汰的数量呈线性下降。在第 5 周（线性）和第 11 周（二次），随着 SD 的增加，H/L 比值增加。在第 8 周，40 公斤/米处理组的 H/L 比值最高（二次）。在第 8 周，随着 SD 的增加，在喂食器、休息和总干扰处的鸡的百分比呈线性增加。随着 SD 的增加，站立、行走和垫料啄的鸡的百分比呈线性下降，而总攻击性行为（战斗和攻击性啄的总和）减少（二次）。在第 11 周，在饮水器处的鸡的百分比随着 SD 的增加而降低，而休息、羽毛啄和严重干扰随着 SD 的增加而增加。垫料湿度随 SD 的增加呈线性增加（第 11 周）。土耳其母鸡的健康和福利受到更高 SD 的负面影响。在低 SD 下，攻击性明显更强，这也可能影响福利。
