During the first experiment we shipped pigs for 30 hours at TQA recommended space allowances plus an extra 20%, which is common practice when shipping breeding gilts. Every 6 hours we assessed health and well-being of the gilts by measuring weight loss, dehydration, stress levels, and blood chemistry parameters. During the second experiment we compared 2 space allowances, TQA recommended space allowance and TQA +20% recommended space allowance. In each study a group of gilts remained in their home pen to serve as controls. At the end of each study gilts were returned to the TTU herd as replacements and their reproductive performance was assessed.
In both studies a similar pattern in the physiological response to transport was observed in the gilts. An initial negative response to transport was followed by an adaption period, and then as the transport period increased a gradual increase in the number of physiological changes that differed from control gilt was observed. Space allowance (TQA and TQA +20%) did not affect any of the measured variables. After a 6 and 12 hour transport period there were significant changes in cortisol concentrations, neutrophil to lymphocyte ratio, and glucose concentrations. These changes suggest an acute stress response to transportation at 6 and 12 hours. After a 6 hour transport period total protein and weight loss were significantly different compared with control gilts, suggesting that transported pigs were experiencing dehydration. Changes in aspartate aminotransferase, creatine kinase, and blood urea nitrogen concentrations at transport durations longer than 6 hours indicate increasing fatigue as a response to physical activity and possibly tissue damage. Reproductive performance (measured as farrowing rate, total born, born alive, stillborn, mummies, weight at processing, number weaned, and weight at weaning) was not affected by transport or duration of transportation in either of the studies.