Date Full Report Received03/13/2008
Date Abstract Report Received03/13/2008
Funded ByNational Pork Board
Currently there are no trucking quality assurance recommendations for space allowance of weaned pigs during transport. The objective of this research was to establish a first estimate of the space requirements of weaned pigs during transport in winter, summer, and spring/fall based on measures of animal well-being. A commercial semi-trailer was fitted with compartments that provided 0.5, 0.6, and 0.7 square feet per pig (on the upper and lower deck) with a constant 100 pigs per compartment. Cameras were placed in each experimental compartment to record behaviors and postures of the pigs during transport. The frequencies of standing, lying, sitting, standing on another pig, and lying/huddling on top of another pig were recorded every minute during the entire duration of transport to determine if space allowance affected the behavior of pigs during transport. Blood samples were taken and weights and lesion scores recorded from 32 pigs per space allowance for physiological and immune measures before and after transport (n = 32 pigs/treatment) per season. This study was replicated over all 4 seasons. Blood samples were analyzed for cortisol concentrations, blood chemistry values, and immune measures. These variables were chosen as they can all change in response to stress in pigs. Body weight was measured as changes in body weight can be used as an indication of dehydration. Finally, lesion scores were used as an indicator of fighting or extreme crowding during transport. Pigs were transported between 60 and 142 min to the wean-to-finishing site using the same route each season. Temperature and relatively humidity for each season were; 10.5±6.15ºC and 44.8±9.71% (winter), 28.4±1.23 ºC and 59.8±4.42 % (summer), 20.4±4.00ºC and 52.7±10.82% (fall), and 22.0±2.49ºC and 58.5±10.48 % (spring). The neutrophil to lymphocyte ratio and cortisol concentrations were elevated in pigs after transport regardless of space allowance or season, suggesting that these pigs were experiencing stress. The blood chemistry measures, blood urea nitrogen, total protein, albumin, aspartate aminotransferase, and creatine kinase were elevated and body weight was reduced in pigs after transport, suggesting that these pigs were experiencing mild dehydration and mild muscle break down due to transport, however space allowance did not further impact these blood chemistry values regardless of season. All blood chemistry values were within the upper limit of the normal range for pigs after transport, but were significantly greater than values prior to transport, suggesting that transport affected the physiology of the pig but did not compromise the welfare of these animals. Different space allowances during transport did not influence any performance or physiological measures measured in this study regardless of season, except in summer the higher neutrophil to lymphocyte ratio in pigs transported at 0.5 ft2/pig, suggest that space allowances of 0.6 and 0.7 ft2/pig are preferable when transporting pigs in summer. Decreased standing behavior performed by pigs transported at 0.6 ft2/pig in winter, decreased lying behavior performed by pigs transported at 0.5 ft2/pig in summer, and increased sitting behavior performed by pigs transported at 0.5 ft2/pig in fall and spring, suggests that space allowances of 0.6 or 0.7 ft2/pig is preferable to 0.5 ft2/pig when transporting weaned pigs in winter, summer, fall or spring.