Use of two novel trailer types for transportation of pigs to slaughter. II. Effects on trailer microclimate, pig behaviour, physiological response, and meat quality under Canadian winter conditions

Abstract

In total, 3654 market pigs were transported to slaughter in winter (six replicates/treatment; January–February in southwestern Ontario) using three trailers: a modified triple-deck pot-belly (MPB), an advanced flat-deck (AFD) trailer, and a standard pot-belly (SPB). Within trailers, ambient conditions, temperature (T °C), relative humidity (RH%), and temperature humidity index (THI) were monitored in three compartments (bottom front (BF), middle middle deck (MM), and top rear (TR)). In total, 162 pigs were selected for the analysis of hematocrit, lactate, and creatine kinase (CK) levels in exsanguination blood and for the evaluation of pork quality as assessed in the longissimus (LM), semimembranosus (SM), and adductor (AD) muscles. The SPB trailer overall was approximately 2.5 °C warmer ( P = 0.01) compared to the MPB and AFD trailers while stationary at the farm. No differences ( P > 0.10) in blood variables were found between trailers. The pHu value of the SM muscle was greater ( P = 0.05) for pigs transported in the SPB trailer than in the AFD and MPB trailers. Given the few substantial effects of trailer models on animal welfare and meat quality, these three trailer models can be used indifferently for short-distance transportation in winter conditions in Canada.