Struwe F J, Gleaves E W, Douglas J H
Department of Animal Sciences, University of Nebraska, Lincoln 68583-0908.
Poult Sci. 1992 Jul;71(7):1154-62. doi: 10.3382/ps.0711154.
Stress in poultry is difficult to define and measure. There is general agreement that some modern poultry production practices may exert a certain amount of stress on birds. Three experiments were conducted to explore possible measures of stress associated with beak trimming and rearing schemes. Experiments 1 and 2 examined different degrees of beak trimming and rearing schemes of wire floor versus litter floor in pullet production. Experiment 3 examined the effect of beak trimming on feed consumption for 14 days after trimming. Adrenal glands of untrimmed birds were heavier (P less than .05) than those of trimmed birds at the end of the pullet growing period in Experiments 1 and 2, evidence that beak trimming reduced overall chronic stress levels. Hearts of untrimmed birds were heavier (P less than .05) than those of trimmed birds in Experiment 1. Hearts and spleens were not affected in Experiment 2. In comparisons of rearing schemes (litter versus wire), birds grown on litter floors had heavier adrenal glands and a greater incidence of cannibalism in the later weeks of Experiments 1 and 2. This indicated that a stressful interaction among penmates had occurred. Birds grown on litter floors consumed more feed than those grown on wire, and the untrimmed birds from both floor types consumed more total feed than trimmed birds. By the end of the growing period, body weights were not different in either study, indicating compensation for any early beak trimming stress. Beak trimming produced a decrease in feed intake in Experiment 3, consumption was reduced (P less than .05) in 5 of the first 8 days after trimming.
家禽的应激难以定义和测量。人们普遍认为，一些现代家禽生产方式可能会给禽类带来一定程度的应激。进行了三项实验，以探索与断喙和饲养方式相关的应激的可能测量方法。实验1和实验2研究了蛋鸡生产中断喙程度的不同以及网上平养与垫料平养的饲养方式。实验3研究了断喙对断喙后14天饲料消耗的影响。在实验1和实验2中，在蛋鸡生长期末期，未断喙鸡的肾上腺比断喙鸡的更重（P小于0.05），这证明断喙降低了总体慢性应激水平。在实验1中，未断喙鸡的心脏比断喙鸡的更重（P小于0.05）。在实验2中，心脏和脾脏未受影响。在饲养方式（垫料与网上）的比较中，在实验1和实验2的后期，在垫料上饲养的鸡肾上腺更重，同类相食的发生率更高。这表明同栏鸡之间发生了应激性相互作用。在垫料上饲养的鸡比在网上饲养的鸡消耗更多的饲料，并且两种饲养方式下的未断喙鸡比断喙鸡消耗的总饲料更多。到生长期末期，两项研究中的体重均无差异，这表明对早期断喙应激有补偿作用。在实验3中，断喙导致采食量下降，断喙后的前8天中有5天采食量减少（P小于0.05）。
