The Impact of the Trailer Microclimate on Some Physiological, Behavioral, and Meat pH of Fattening Pigs During Short‐Duration Journeys in Tropical Climate.

Heat stress is a problem that negatively affects animal welfare, health, and the productive efficiency of pigs. The objective of the study was to evaluate the effect of the trailer microclimate on some physiological, behavioral, and meat pH of fattening pigs during short‐duration journeys. Eight journeys (n = 216 pigs) of short duration (51.6 km and 1.5 h), originating from the same farm, were evaluated with a stocking density of 0.57 (±0.04) m2/100 kg (mean BW: 116.1 ± 7.52 kg). The thermal profile of the load (THI) was recorded in the four compartments of the truck. Upon arrival at the slaughterhouse, unloading was evaluated, and the percentage of nonambulatory pigs, mortality, and body temperature were recorded. Blood samples were obtained during exsanguination and the pH45 was measured. Overall, THI values recorded in all four compartments were below the threshold considered conducive to heat stress in pigs (23.9°C and THI ≤ 74). Serum concentrations of cortisol and the neutrophil/lymphocyte (N/L) ratio were above concentrations considered normal for the species (p < 0.05) and no significant differences were observed in average meat pH45 values according to the truck compartment (p > 0.05). The planning of transport in the morning hours and the consideration of the thermal environment of the truck is essential to reduce heat stress, economic losses, and negative effects on meat quality. [ABSTRACT FROM AUTHOR]