Ranging behaviour in organic layers and broilers and the relationship with welfare

Offering chickens the possibility to roam outdoors aims to improve their welfare in the chicken industry. But, not all chickens use to range to the full extent. Whether variation in ranging behaviour of chicken is related to their welfare is not fully understood, partly because ranging behaviour of individuals in a flock is difficult to record. At the ILVO research facility in Belgium, we housed 400 slow growing broiler Sasso chicken in 4 mobile houses (n=100 per house) in 2016 and 202 organic Novogen layers in 2 mobile house (51 per department of the house) from 2018-2019. The range consisted of a forest-like area and a grassland area. We assessed ranging patterns of slow growing broilers and layers by automatic tracking recordings. Ten out of 100 broilers were tracked with Ultra wide band tracking, whereby we were able to monitor their exact location every 6 minutes. All 202 layers were tracked with RFID tracking, whereby we could monitor their presence at current located antennas spread over the range. All animals were assessed for welfare scoring based on development of physical injuries and on fear responses. Physical injuries entailed presence of hock burns, food pad dermatitis and walking disabilities in the broilers. Physical injuries in the layers entailed presence of comb lesions, food pad dermatitis, feather or integument damages and keel bone damage. Our preliminary analysis, does not show relationships between ranging and development of welfare problems in the slow growing broilers or in the layer birds. For both groups, the majority of our birds score relatively low on welfare issues as compared to the scale of severity (e.g. max of 2 gait score for the broilers in a scoring system to 5). We did, however, find variation in ranging patterns over time, with some birds ranging far and often, while others remained close and sporadically ventured further out. Continuing our analysis, we hope to provide answers to the variation in ranging and its relationship with welfare, and the change in preference for certain areas in the range over time.