A cross-sectional study of the prevalence of vent pecking in laying hens in alternative systems and its associations with feather pecking, management and disease

The aim of this cross-sectional study was to investigate associations between vent pecking (VP) and management in laying hens in alternative systems and to compare the results with those from the feather pecking (FP) analysis using data collected in the same study [Vet. Rec. 147 (2000) 233]. The data were derived from a postal questionnaire carried out on commercial flocks in Great Britain in 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%. Of 198 respondents, 36.9% of the farmers reported that vent pecking had occurred in the last depopulated flock and 33.3% had both vent pecking and feather pecking. The outcome variable, vent pecking after point of lay, was compared with exposures significant at P=0.05 in univariate statistics in a backward elimination logistic regression model. The final model contained four factors that increased the risk of vent pecking: dim light to encourage the use of nest boxes, diet changed three or more times during the laying period, the use of hanging bell drinkers and onset of lay before 20 weeks of age. The first three factors in this model were also significant factors that increased the risk of feather pecking in a logistic regression model developed by Green et al. [Vet. Rec. 147 (2000) 233]. The results indicate that vent pecking and feather pecking may share common environmental risk factors in commercial flocks.