Effects of fully or partially slatted flooring designs on the performance, welfare and carcass characteristics of broiler chickens.

1. The objective of this study was to evaluate the effects of fully (FSF) or partially (PSF) flooring designs on animal-based welfare indicators in a fast-growing broiler genotype. Growth performance and carcass characteristics were assessed.2. One-d-old male chicks were randomly assigned to three groups: fully slatted flooring (100% slatted floor), partially slatted flooring (50% litter floor and 50% slatted floor) and conventional floor pens with litter (control, 100% deep litter) with 5 replicates of 14 male chicks. The litter was rice hull, as is usual in practice.3. Measurements of live body weight, feed intake, feed conversion ratio, mortality and performance index were collected before depopulation at 42 d old. Welfare assessments were done by individual ante- and post-mortem carcass inspection during depopulation and after slaughter.4. Broiler live body weight (P < 0.03) and feed intake (P < 0.003) and ante-mortem welfare indicators (P < 0.001) were positively affected by FSF and PSF compared to the conventional deep litter system. Post-mortem lesion scores on wings and shoulder were similar in all floor types but there were significant differences for the lesions on breast (P < 0.003) and pygostyle (P < 0.05).5. In conclusion, FSF and PSF resulted in higher body weights, while reducing incidence of foot pad and hock joint deformations in live animals.