Post-weaning weight gain in pigs is not affected by moderate duration transport at 20 days of age.

Transportation at weaning is an integral component of the American swine industry. However, the long-term effects on growth performance have not been well characterized. Previous research suggests transportation causes weight loss immediately following weaning, but few studies have followed this effect further than 7 d post-weaning, with transport causing decreased body weight in those that have. In experiment 1, average weight pigs at 20 ± 1.3 d of age were weaned and either 1) transported for 9 hour without feed and water (TR), 2) had their feed and water restricted for 9 hour (FR), or 3) were weaned and provided immediate access to feed and water (WN). Subsequent weight gain was tracked to market. No differences in body weight (BW) or average daily gain (ADG) were observed among treatment groups. In experiment 2, low (LBW), average (ABW), and high body weight (HBW) pigs at 20.7 ± 1.2 d of age were weaned and either transported for 9 hour (TR) or weaned without transport (WN) and placed in a nursery with access to feed and water to determine if the response to weaning and transport stressors was influenced by weaning weight. While TR pigs regardless of weight class did lose a larger percentage of their weight after 9 hour (P < 0.001), by 7 d post-weaning that effect had disappeared (P > 0.10). The BW gap between ABW and HBW pigs as a proportion of BW decreased with age, but LBW pigs remained lighter than the other two weight classes (P < 0.01). Additionally, ADG was lower in the nursery period (P < 0.05) and tended to be lower in the grow-finish period (P = 0.062) for LBW pigs at weaning, causing them to continue to fall behind their larger counterparts. While this research found no effect of transportation on long-term growth, it suggests that weaning weight is a meaningful predictor of future body weight in the grow-finish phase.