Activity tracking and gait scoring

Gait, or walking ability, is often recorded for broilers as an indicator for leg health. Gait recordings are often performed manually, which can be time-consuming and subjective. Therefore, there is an interest in automated measuring of (alternative) traits that can be used as a proxy for leg health. One trait that has potential to provide indications for broiler gait is locomotor activity.

An automated activity tracking system, which was implemented within the Breed4Food project ‘Individual Tracking’, was used to record individual activity of 137 broilers from approximately 16 to 32 days old. At the end of the tracking period, the gait of each bird was scored by an expert. Gait was scored on a scale of 0 (best) to 5 (worst). Scores 0-2 were considered “good” and scores 3-5 were considered “suboptimal”.

Birds with a good gait appear more active

The activity of birds with a good gait was compared to that of birds with a suboptimal gait. Birds with a good gait showed higher activity at the start of the tracking period, at the end of the tracking and when averaging across the full tracking period. In subsequent analyses, the body weight of the birds was taken into account, based on a classification of heavy versus light at approximately two weeks old, as well as the day of tracking, trial and cross of the birds. Within the lightweight birds, the birds with a good gait were again more active than the birds with a suboptimal gait. For heavyweight birds, no difference in activity was found.

Conclusion

Overall, this study indicates that birds with different gait classifications show differences in average activity levels. However, there was quite some overlap in activity levels between the two gait groups, which complicated distinguishing broilers with different gaits using information on activity levels only. Therefore, more research is required to, in the future, potentially be able to completely distinguish between good gait and suboptimal gait broilers.

This was a joint WUR and Utrecht University study, in collaboration with Cobb Europe and Breed4Food, and was recently published in the scientific journal Poultry Science.