On-farm study of walking ability in conventional broilers and those labelled as being higher welfare

Multiple factors, including genetics and management practices, are known to influence the walking ability of broilers. This field survey aimed to assess the walking ability of broilers in two different production systems.

Thirty flocks of conventional (Ross 308) and 26 flocks of welfare-labelled (Level 1; Ranger Gold/Rustic Gold) broilers were evaluated, with maximum stocking densities of 40 and 38/38 kg/m² and growth rates of 62-63 g/day and 43-45/47-51 g/day, respectively. Gait scores were obtained for approximately 120 birds/flock prior to slaughter using the six-point Bristol scale, with scores ranging from 0 (no detectable abnormality) to 5 (complete lameness). Data on broiler age, target bodyweight on day of assessment and genotype were collected.

The odds of birds having gait scores greater than 0 (p = 0.011), 1 (p < 0.001) and 2 (p = 0.033) increased significantly with a 100 g increase in bodyweight for conventional broilers, whereas no such effect was found for level 1 broilers. Within the level 1 system, the slower-growing Ranger Gold birds had lower odds of having gait scores greater than 1 than the faster-growing Rustic Gold birds (p = 0.022).

Data on the bodyweight of individual birds were not collected.

The results obtained in this study are in line with previous research showing that walking ability is negatively associated with growth rate.