Pre-slaughter losses of broilers: effect of time period of the day and lairage time in a subtropical climate

Abstract

Mortality losses of broilers during pre-slaughter operations consists of actual challenge for maintaining world leadership of Brazilian poultry industry. In relation to thermal environment and its influence on abattoirs' handling, some studies has advanced about the knowledge of these variables on poultry welfare. However, few studies was developed in subtropical conditions, considering a joint analysis of involved thermal factors. In this context, the aim of this work was to assess the mortality of broiler chickens transported throughout daily periods and submitted to different lairage time intervals. A trial was conducted in a commercial slaughterhouse at São Paulo state, during 2006. More than 13,000 loads was registered regarding broiler mortality data during pre-slaughter operations, as well as factors which had influence on losses, such as daily periods, lairage time and bioclimatic variables. Higher mortality rates of broiler transportation were registered during afternoon, around 13 birds per truck. Regarding the interaction between daily periods and lairage time at abattoir, during morning and afternoon, the mortality rate was reduced when birds were submitted to a lairage time of two hours in a controlled environment. These results showed the high level of pre-slaughter losses during hottest periods and the importance of environment control during pre-slaughter lairage of broiler chickens, with adoption of increasing time intervals when lairage environment is controlled.