Taylor, Peta S

Hemsworth, Paul H

Groves, Peter J

Gebhardt-Henrich, Sabine G

Rault, Jean-Loup

2018-06-01

Little is known about the effect of accessing an outdoor range on chicken welfare. We tracked individual ranging behavior of 538 mixed-sex Ross 308 chickens on a commercial farm across 4 flocks in winter and summer. Before range access, at 17 to 19 d of age, and post-range access, at 30 to 33 and 42 to 46 d of age in winter and summer flocks respectively, welfare indicators were measured on chickens (pre-range: winter N = 292; summer N = 280; post-range: winter N = 131; summer N = 140), including weight, gait score, dermatitis and plumage condition. Post-ranging autopsies were performed (winter: N = 170; summer: N = 60) to assess breast burn, leg health, and ascites. Fewer chickens accessed the range in winter flocks (32.5%) than summer flocks (82.1%). Few relationships between welfare and ranging were identified in winter, likely due to minimal ranging and the earlier age of post-ranging data collection compared to summer flocks. In summer flocks prior to range access, chickens that accessed the range weighed 4.9% less (<i>P</i> = 0.03) than chickens that did not access the range. Pre-ranging weight, gait score, and overall plumage cover predicted the amount of range use by ranging chickens in summer flocks (<i>P</i> < 0.01), but it explained less than 5% of the variation, suggesting other factors are associated with ranging behavior. In summer flocks post-range access, ranging chickens weighed 12.8% less than non-ranging chickens (<i>P</i> < 0.001). More range visits were associated with lower weight (<i>P</i> < 0.01), improved gait scores (<i>P</i> = 0.02), greater breast plumage cover (<i>P</i> = 0.02), lower ascites index (P = 0.01), and less pericardial fluid (<i>P</i> = 0.04). More time spent on the range was associated with lower weight (<i>P</i> < 0.01) and better gait scores (<i>P</i> < 0.01). These results suggest that accessing an outdoor range in summer is partly related to changes in broiler chicken welfare. Further investigations are required to determine causation.

Poultry Science, 97(6), p. 1861-1871

1525-3171

0032-5791

29528464

https://hdl.handle.net/1959.11/30929

Elsevier BV

Attribution-NonCommercial-NoDerivatives 4.0 International

Ranging behavior relates to welfare indicators pre- and post-range access in commercial free-range broilers

Journal Article

Publication