Effects of cooled perch and different floor types on animal- and management-based welfare indicators, heterophil/lymphocyte ratio, and perching behavior in broiler chickens reared at high ambient temperature

This study aims to analyze the impact of cooled perches and different floor types on broiler chicken welfare under high ambient temperatures. The experiment was designed as a 2 × 3 factorial arrangement with 234 male broiler chickens. They were randomly assigned to two perch treatments (cooled and non-cooled) and three-floor treatments (slatted floor, zeolite, and wood shavings) with three replicates consisting of 13 broiler chickens each. The presence of cooled perches increased (P < 0.0001) the incidence of foot pad dermatitis. The incidence of foot pad dermatitis and hock burn in the treatment of slatted floor was higher (P < 0.0001). The litter moisture concentration was lower in the zeolite treatment at the end of the trial (P < 0.0001). Cooled perch availability in hot weather reduced (P = 0.006) the heterophil-lymphocyte ratio, indicating reduced stress levels. No significant effect of the floor types on stress levels was observed. Notably, an increase in perch-contacting behavior was observed in the presence of cooled perches (3rd, 4th, and 5th weeks P < 0.0001). In brief, cooled perches increased perch-contacting behavior and mitigated stress but increased foot pad dermatitis. Slatted floors negatively impacted footpad and hock health.