Welfare of broiler chickens reared under two different types of housing

We compared closed- and open-sided industrial houses with respect to the welfare of broiler chickens in southern Brazil.Ten flocks from each design were evaluated and measures divided into the following categories: i) bird health: contact dermatitis on the breast and abdominal areas, bird soiling, foot-pad dermatitis, hock burn, lameness, fractures, bruising, scratches, dead on arrival, diseases; ii) environmental measurements: relative humidity, temperature, air velocity, ammonia (NH3), carbon dioxide (CO2), light intensity, litter moisture; iii) behaviour: bird behaviour, touch test; and iv) affective states: qualitative behaviour assessment. Closed-sided houses showed worse contact dermatitis on the breast and abdominal areas, lower exploratory behaviour prevalence, higher NH3 (11.2 [+/- 6.8] vs 7.5 [+/- 3.9] ppm) and CO2 (1,124.9 [+/- 561.5] vs 841.0 [+/- 158.0] ppm), lower light intensity (6.9 [+/- 6.3] vs 274.2 [+/- 241.9] lux), while open-sided houses had a higher prevalence for scratches and panting behaviour, and lower air velocity (2.1 [+/- 0.7] vs 1.1 [+/- 1.0] m s(-1)). Stocking densities of 13.9 (+/- 0.4) and 12.0 (+/- 0.3) per m(2) for closed- and open-sided houses, respectively, likely influenced some results. All values shown are means (+/- SD). Even though open-sided houses presented fewer animal welfare restrictions (according to five indicators as opposed to three for closed-sided houses), both revealed important welfare problems, evidenced by poor environmental indicators, behavioural restrictions and injuries