Association between in-transit loss, internal trailer temperature, and distance traveled by Ontario market hogs.

An observational study was conducted from July to October 2004 to determine the association between in-transit losses of swine and internal trailer temperature after controlling for loading density, trip distance, herd size, and random trip effect. A convenience sample of 3 trucking companies was used to collect temperature, relative humidity, and global positioning data for 104 trips that delivered 21,834 pigs from 371 producers to Ontario abattoirs. The association between in-transit loss and trailer temperature was determined using the 90th percentiles of internal temperature for each trip. Average loading density was 0.36 m2/100 kg pig (range 0.28 to 0.50 m2/100 kg pig). Average in-transit loss was 0.12%; however, 94% of producers experienced no losses. As the 90th percentile of internal trailer temperature increased from a range of 8.6 degrees C to 23.3 degrees C to a range of 23.4 degrees C to 26.1degreesC, average in-transit loss ratio increased approximately 3-fold, with an additional 2-fold increase as the range increased from 26.2 degrees C to 28.9 degrees C to 29.0 degrees C to 30.5 degrees C. As the 90th percentile of temperature increased by 1degreesC over the full range of temperatures in this study, in-transit loss was expected to increase 1.26 times. The in-transit loss was expected to decrease 0.81 times for each 50-km increase in distance traveled between the farm and the abattoir.