Prevalence of leg weakness in broiler chickens and its relationship with genotype

TLDR

The study developed a method to assess leg‑weakness prevalence in broilers by evaluating their walking ability. The method categorizes walking ability into six levels and was applied to free‑range and three commercial broiler breeds to estimate leg‑weakness prevalence. The method yielded consistent results, revealing that 90 % of commercial broilers displayed gait abnormalities, 26 % were severely affected, and genetic factors and liveweight were linked to leg weakness.

Abstract

A method for measuring the prevalence of leg weakness by assessing the walking ability of broilers was developed. Walking ability was divided into six categories, from completely normal to immobile. The method was found to give consistent results when performed by the same people. In a survey of commercial, intensively reared broilers, 90 per cent had a detectable gait abnormality and 26 per cent suffered an abnormality of sufficient severity for their welfare to be considered compromised. The prevalence of leg weakness in free range broilers, and three commercial breeds of broilers was determined. The results indicated that genetic factors were an important cause of leg weakness in broilers and also identified a possible relationship between liveweight and leg weakness.