Epidemiology of a contact dermatitis of broilers.

A computerised information retrieval system of broiler production data has been used to study the epidemiology of contact dermatitis. The results of the analyses of broiler production data for the period 1984/85 were compared and contrasted with those for the period 1986/1987. The prevalence of breast lesions recorded in the latter period was 33% less than in the former. The prevalence of hock lesions was similar in both periods, but the degree of variation in the prevalence of lesions recorded by individual flocks was substantially reduced in 1986/87. Stocking density, average age of removal and the sex of birds all had an effect on the prevalence of the condition in broiler flocks in both time periods. The condition was more frequently recorded in flocks during the winter and a strong correlation with ambient relative humidity, obtained.