Green L E, Lewis K, Kimpton A, Nicol C J
Department of Biological Sciences, University of Warwick, Coventry.
Vet Rec. 2000 Aug 26;147(9):233-8. doi: 10.1136/vr.147.9.233.
A cross-sectional study of risk factors for feather pecking in layings hens in alternative systems was carried out in July 1998. A total of 637 questionnaires were sent out to farmers and producer groups and, after two reminders, the final response rate was 51.5 per cent. The outcome variable was feather pecking after point of lay. Over 55 per cent of the farmers reported that feather pecking had occurred in the last depopulated flock. This outcome was compared with the management procedures reported by flock managers by using univariate statistics. Factors associated with feather pecking with a significance < or = 0.05 were then tested in two logistic regression models. In the first model the following factors were associated with an increased risk of feather pecking: less than 50 per cent of the flock using the outdoor area on a fine and sunny day, the occurrence of egg peritonitis and the occurrence of infectious bronchitis. The direction of the association between feather pecking and these infectious diseases was unclear, so in the second model only factors which were consistent throughout the laying period were tested. The following factors were associated with an increased risk of feather pecking: less than 50 per cent of the flock using the outdoor area on a fine and sunny day; three or more changes of diet during lay; the inspection of the flock by one person; an absence of loose litter at the end of lay; a temperature in the hen house of less than 20 degrees C; turning the lights up when the flock was inspected; and the use of bell-drinkers. It is concluded that some of these factors could inhibit foraging and dust-bathing behaviour and others may increase competition or frustration, both of these changes having been shown experimentally to initiate feather pecking behaviour.
1998年7月，针对替代养殖系统中蛋鸡啄羽风险因素开展了一项横断面研究。共向养殖户和生产者团体发放了637份调查问卷，在经过两次催问后，最终回复率为51.5%。结果变量是产蛋后啄羽情况。超过55%的养殖户报告称，在上一批淘汰鸡群中发生过啄羽现象。通过单变量统计，将这一结果与鸡群管理者报告的管理程序进行了比较。然后，在两个逻辑回归模型中对与啄羽相关且显著性≤0.05的因素进行了检验。在第一个模型中，以下因素与啄羽风险增加相关：在晴朗的日子里，不到50%的鸡群使用室外活动区域、发生卵黄性腹膜炎以及发生传染性支气管炎。啄羽与这些传染病之间关联的方向尚不清楚，因此在第二个模型中，仅对整个产蛋期都一致的因素进行了检验。以下因素与啄羽风险增加相关：在晴朗的日子里，不到50%的鸡群使用室外活动区域；产蛋期间饲料更换三次或更多次；由一人检查鸡群；产蛋末期没有松散的垫料；鸡舍温度低于20摄氏度；检查鸡群时开灯；以及使用钟形饮水器。研究得出结论，其中一些因素可能会抑制觅食和沙浴行为，而其他一些因素可能会增加竞争或挫折感，实验表明这两种变化都会引发啄羽行为。
