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

Abstract

A total of 3366 pigs were transported to slaughter in summer (six replicates/trailer type; July-August in southwestern Ontario) using three trailers: a modified triple-deck pot-belly (MPB), an advanced flat-deck (AFD), 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 deck, MM, and top rear, TR). A total of 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 AFD and MPB trailers presented lower ( P < 0.01) T°C and THI compared to the SPB during transit. In the SPB trailer, pigs transported in the MM compartment showed higher ( P < 0.01) blood CK concentrations than those transported in the BF compartment and lower pHu values in the SM and AD muscles ( P = 0.02 and P = 0.04, respectively) than those transported in the TR compartment. Although the AFD trailer design provided a better microclimate for pigs, the improvements in the design of the novel trailers only slightly reduced stress in pigs during summer transits.