Broiler trailer thermal conditions during cold climate transport

Abstract

Burlinguette, N. A., Strawford, M. L., Watts, J. M., Classen, H. L., Shand, P. J. and Crowe, T. G. 2012. Broiler trailer thermal conditions during cold climate transport. Can. J. Anim. Sci. 92: 109–122. Thermal environments within broiler transport vehicles are dependent on ambient conditions and, if poorly managed, can be a welfare concern. To effectively manage broiler transport, the environmental conditions throughout vehicles must be understood. Under standard commercial practices, temperature and humidity levels in double-trailer broiler vehicles were examined for a range of ambient temperatures (−24 to 11°C). During warmer ambient conditions (9.8°C) trailer roof vents and side curtains were all open, which resulted in a narrowing of the on-board temperature range (10.3 to 16.7°C). As ambient temperature cooled side curtains and some of the roof vents were closed. This resulted in increasingly variable and more extreme thermal conditions, with heat and moisture accumulated along the midline of the load near the front of the lead trailer and near the back of the rear trailer. At an ambient temperature of −22.1°C trailer temperatures ranged from −20.7 to 21.7°C with an estimated 58.6% of the load volume being exposed to temperatures below 0°C. In addition, the trailer humidity ratio rose 14.0 g kg−1 above ambient and conditions approached saturation (RH>80%) in 55.2% of the load volume. These results support the need to find a means to remove moisture and redistribute heat on broiler trailers during cold ambient conditions.

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

“…Another important factor that reduces ventilation within the trailer is the use of tarpaulins along the sides of the trailer to protect the birds on the outside of the load from cold temperature, wind chill, and precipitation. In a closed or partially closed ventilation configuration, internal temperature and humidity can rise at one or more locations within the vehicle (Kettlewell et al 1993;Mitchell and Kettlewell 1998;Burlinguette et al 2012). In this study, there was no indication that the temperature within the trailers increased as a result of fully closed tarpaulins to the extent that would have caused hyperthermia.…”

“…Unless the humidity was high, there was high stocking density and inadequate ventilation, this maximum external temperature in itself would not have posed significant challenges to the broilers . However, the external temperature and humidity during a journey do not necessarily provide a good indication of the environmental conditions experienced by the broilers within the module on the trailer (Knezacek et al 2010;Burlinguette et al 2012). Unfortunately for many loads, the temperature recordings provided from sensors placed along the roof of the trailer did not provide a good profile of the temperature conditions within the trailer during the journey, and there was no measure of humidity within the trailer.…”

Trailer microclimate and calf welfare during fall-run transportation of beef calves in Alberta1,2

“…Under commercial conditions, similar loads (e.g., similar space allowances, compartments, etc.) with different ambient conditions can be combined for comparison of transportation factors on microclimate through comparison of the difference between ceiling-level and ambient temperature and humidity ratio during steadystate periods (Brown et al, 2011;Burlinguette et al, 2012). The interval of 30 to 60 min after leaving the origin location was selected to evaluate the effect of transportation factors on in-transit microclimate as it represented a period of time when all loads were traveling, had been loaded for approximately the same interval, and were most likely to have steady-state conditions based on less than 5°C deviation in temperature within locations and less than 5°C change in the difference between inside and outside of the trailer.…”

“…The interval of 30 to 60 min after leaving the origin location was selected to evaluate the effect of transportation factors on in-transit microclimate as it represented a period of time when all loads were traveling, had been loaded for approximately the same interval, and were most likely to have steady-state conditions based on less than 5°C deviation in temperature within locations and less than 5°C change in the difference between inside and outside of the trailer. The methods of identifying steady-state periods are similar to methods used in evaluation of microclimate during commercial transport of poultry (Burlinguette et al, 2012) and swine (Brown et al, 2011). At each minute within the interval of 30 to 60 min after leaving the origin, the temperature and humidity ratio mean was taken across all loggers at compartment ceiling-level and outside locations within each load and compartment (e.g., data from all compartment ceiling-level loggers within a compartment of a load were averaged together to represent conditions at compartment level).…”

Severe hypothermia in transported pullets: case study of its occurrence, diagnosis and treatment using active external rewarming technique

“…Transportation of matured live birds by road is an inevitable component of the poultry industry. Unfortunately, transportation induces severe stress in birds; which may cause their suffering or death, especially when it is done under extreme and/or unethical conditions (Minka & Ayo 2008Burlinguette et al 2011). Heat and cold are two major stress factors contributing to both death and overall adverse effects of road transportation stress in poultry (Minka & Ayo 2008;Knezacek et al 2010;Burlinguette et al 2011).…”