The Effects of Perch Cooling on Behavior, Welfare Criteria, Performance, and Litter Quality of Broilers Reared at High Temperatures with Different Litter Thicknesses

ABSTRACT

The first aim of this study was to investigate the effects of perch cooling and different litter thicknesses on litter quality of the housing facility, welfare criteria (incidence of footpad and hock burns, gait score, plumage cleanliness and damages), heterophil/lymphocyte ratio, growth, and carcass compositions of broilers reared at high ambient temperature. Secondly, the study was conducted to determine whether cooled perches would be preferred by broiler chickens exposed to a hot environment, and subsequently, whether the utilization of these perches would improve the welfare and performance of broilers, beyond those provided by non-cooled perches. A total of 459 1-day-old male broiler chicks were randomly assigned to nine treatment groups based on the perch treatment (no perch, non-cooled, cooled perches) and litter thicknesses (1, 7, 14 cm) with three replicates. Aerial ammonia and litter moisture levels were lower in broilers reared at 14 cm litter thickness group than in broilers reared at 1 cm thickness group. The perch-contact incidence of chickens reared under the cooled perch was found higher than the non-cooled chickens at 36 to 42 days of age. Cooled perches and 14 cm of litter thickness tended to decrease the incidence of footpad and hock burn. The body weight gain of the broilers in cooled perch group was higher than those in no perch and non-cooled perch groups at 0-42 d (p 0.05). These results suggest that cool perches have a beneficial effect on the performance and welfare of broilers.