Injury and mortality in broilers during handling and transport to slaughter

Abstract

Multiple factors affect the risk of broiler injury and mortality during loading, transport, and lairage. These include the physical and pathophysiological condition of broilers before loading and the type of handling procedures used. The external environmental conditions have a major influence on the risk of mortality. Combinations of high stocking density, insufficient ventilation, and high temperature and humidity pose a risk of hyperthermia. Combinations of wet conditions, cold temperature, and air movement, increase the risk of hypothermia. However, protection from cold and wet conditions involves the use of side protection that restricts the trailer ventilation that can cause heat and moisture to build up in the load, increasing the risk of hyperthermia. Modular systems reduce the risk of injury and facilitate unloading into a lairage where temperature and ventilation can be controlled. The duration of loading, transport, and lairage increases the mortality risk. Deaths can occur during each stage and interactions between the duration of the preslaughter stages, the thermal environment, fasting, ill-health, and injury can reduce the physiological capacity of the birds to maintain homoeostasis resulting in exhaustion and death. Quality control and action on the identified risk factors should reduce injury and mortality during preslaughter handling and transport.

Risk factors for bruising and mortality of broilers during manual handling, module loading, transport, and lairage

“…The median DOA % for broilers in study 1 was lower than the mean DOA % reported for all poultry slaughtered in Canadian federally inspected plants (0.22%) and in those slaughtered in Atlantic Canada (0.23%) in 2014 (Agriculture and Agri-Food Canada 2017). The DOA % reported in most studies in Europe is about 0.2% (Cockram and Dulal 2018). Although we were dependent on the processing plant to facilitate the on-farm observations and to provide data, we received excellent assistance, all data were readily provided, and we had no reason to question the representativeness of the data collected.…”

“…In Canada, in 2017, the average mortality [deadon-arrival (DOA)] of the 659 million broilers transported from farm to a federally inspected processing plant was 0.2% (Agriculture and Agri-Food Canada 2017). This mortality has financial and animal welfare implications (Cockram and Dulal 2018). As multiple factors affect the risk of bruising and mortality of broilers during loading, transport, and lairage (Cockram and Dulal 2018), further information is required on how these factors interact during specific environmental conditions and industry practices.…”

“…This mortality has financial and animal welfare implications (Cockram and Dulal 2018). As multiple factors affect the risk of bruising and mortality of broilers during loading, transport, and lairage (Cockram and Dulal 2018), further information is required on how these factors interact during specific environmental conditions and industry practices. Identification of factors affecting mortality and injury and their relative significance would be useful for continuous improvement in industry practices and for the formulation of codes of practice and the regulation of broiler handling and transport in Canada.…”

“…These include (a) mortality rate during rearing, method of catching, crate stocking density, and weather conditions (Chauvin et al 2011), (b) breed, catching team, loading, and transporting during the day compared with the night, ambient temperatures ≤5 or >15°C and increasing flock size, live weight, module stocking density, journey duration, and lairage duration (Nijdam et al 2004), and (c) bird age and weight, catching team, journey duration and holding barn duration, and cold external temperatures (Caffrey et al 2017). Whether a particular risk factor is identified as significant in a particular study is likely to be dependent on the range of environmental variables, for example, temperature and journey duration, the characteristics of the birds, handling, transport, and lairage procedures, and the robustness of the multivariable analyses (Cockram and Dulal 2018).…”

“…Bruising is a superficial injury that occurs after trauma (Hamdy et al 1961). However, after slaughter and defeathering, it can be difficult to differentiate bruising due to trauma from haemorrhage in muscles that can occur between rearing and processing from causes unrelated to trauma (Kranen et al 2000;Cockram and Dulal 2018). Bruising can also occur at the plant during handling and slaughter (Gregory and Bell 1987;Gregory et al 1989;Gregory 1994).…”