Monitoring leg problems in broilers: a survey of commercial broiler production in Denmark

• Published in: World's poultry science journal 2001-03, Vol.57 (1), p.55-69
• Main Authors: Sanotra, G. S., Lund, J. D., Ersbøll, A. K., Petersen, J. S., Vestergaard, K. S.
• Format: Article
• Language: English
• Subjects: Ammonia burns; Animal welfare; asymmetry; Birds; Body weight; broilers; Burns; chicks; crooked toes; gait; Poultry production; Regional Reports; tibial dyschondroplasia; varus/valgus deformations; walking ability
• ISSN: 0043-9339; 1743-4777
• DOI: 10.1079/WPS20010006

The purpose of this study was to examine the prevalence and the extent of leg problems in broiler chicks reared in conventional production systems in Denmark. The survey, which was designed as a cross-sectional study, included 28 broiler flocks (8% of the total number of flocks in Denmark); 2800 chicks in total (100 chicks per flock) were investigated for the occurrence of leg disorders in relation to animal welfare. The leg disorders included impaired walking ability, tibial dyschondroplasia (TD), varus/valgus deformations, crooked toes, foot pad burns, and asymmetrical development of the tarsometatarsus. The mean prevalence of impaired walking ability (gait score > O), tibial dyschondroplasia (TD score > 0), varus/valgus deformations, crooked toes and foot pad burns was 75.0%, 57.1%, 37.0%, 32.6% and 42.0%, respectively. The risks of the occurrence of these leg problems were significantly influenced by body weight and sex of the chicks. For birds with impaired walking ability (corresponding to gait scores > 0 and >2), significant interactions were found between body weight and sex. Positive correlations (r > 0.20) were found between gait score and TD score, gait score and varus/valgus deformations, TD score and varus/valgus deformations, varus/valgus deformations and body weight, crooked toes and body weight, and between varus/valgus deformations and body weight. Only weak correlations were found between the relative asymmetry in the length, thickness and diameter of the tarsometatarsus and the other leg problems measured. It was concluded that the prevalence of leg problems in broilers in conventional production systems is very high and compromises the welfare of the birds. One of the main factors responsible is their high growth rate.