Rearing, bird type and pre-slaughter transport conditions of broilers II. Effect on foot-pad dermatitis and carcass quality

Abstract

A multivariable linear model was used to analyse the incidence of carcass quality defects over one year in a commercial database that included 1,856 flocks of Ross broilers (9,188 shipments, 1,975,420 carcasses inspected). The incidence of foot-pad dermatitis (FPD), scratches and wing and back haematomas was scored and analysed in terms of the effects of transport distance, arrival time to the slaughterhouse, waiting time at the slaughterhouse, maximum outside temperature on the day of transport, feed conversion rate, stocking density, bird type (yellow-skinned females or males, white-skinned females or males and roaster females), thinning (birds transported after thinning, birds remaining after thinning, and non-thinned flocks), bed litter type (rice hulls, chopped straw or wood shavings), and ventilation system (dynamic, static or tunnel). The incidence of FPD was significantly (p<0.001) lower at higher maximum temperatures and higher in flocks with a higher feed conversion rate. FPD also increased with stocking density (kg/m²) and was, on average, 5.0% higher in males than females. Regarding thinning, FPD was 13% lower in birds transported after thinning. Birds raised on chopped straw had more FPD (49.3%), followed by wood shavings (31.1%). Scratches were higher at higher temperatures and increased with transport distance. Birds transported after thinning had 5.8% more scratches than non-thinned birds, while increased stocking density (kg/m²) on the farm tended to increase scratches. Back haematomas were 32.6% higher in birds that were thinned, while wing haematomas increased with stocking density (kg/m²). Back haematomas were also 23.7% higher in males and more common in white-skinned birds.