Interpretive Summary: Physiological response of weaned piglets to two transport durations observed in a Canadian commercial setting
By: Dr. Emily Taylor
Multi-site pig production is a standard industry practice, though it risks stressing animals during transportation. Most data involving transportation effects was done in market hogs, and the current Canadian transport regulations weigh heavily on these studies' information. Unfortunately, there is minimal data describing the impact duration on weaned piglet welfare. Therefore, additional data on the response of weaned piglets to transport are needed for age-specific evidence-based recommendations.
The objective of the current study was to describe and compare mortality, injury, weight change, hematological or biochemical changes in hydration, muscle injury, and stress response of weaned piglets undergoing short duration (SD; <3h), or long duration (LD, >30h) transport events. Mortality was low during both transport events and did not associate with a given transport duration. All lameness cases were identified as mild in severity, though lesions on ears and skin were more prevalent after transport. Authors suggest that this may have been related to mixing aggression associated with weaning rather than transport alone.
There was a numeric decrease in weights of piglets undergoing LD transport than SD transport, though not significant. Following transport, LD piglets had increased hematocrit levels, and authors suggest this being from an increase in body water losses. Greater levels of muscle injury were seen in SD piglets when compared to LD piglets. More specifically, elevated aspartate aminotransferase and creatine kinase were seen; however, these parameters were within normal ranges. Cortisol and neutrophil to lymphocyte ratios, indicating a physiological stressor, were elevated in SD piglets.
In conclusion, this study demonstrates that both short and long-term transport can result in physiological changes of weaned pigs. Authors suggest investigating transport duration under different environmental conditions as a valuable next step.
This article is available in the Journal of Animal Science.