Stressor factors in the transport of weaned piglets: a review

The transport of weaned piglets is considered an important stress factor since the conditions involved in shipping affect the animals' health and welfare. The principal stressor factors that piglets experience during transport include: mixing with unfamiliar animals, overcrowding, heat, cold, temperature fluctuations, vibrations, and noise. It is well known that all these factors contribute to raising the level of stress caused by the weaning process; however, the additional effects attributable to transport immediately after weaning impact the physiology, metabolism and behaviour of piglets, predisposing them to delayed growth. For this reason, animal transport must be well-planned and take into account such aspects as preparation of the piglets, choosing the best route and vehicle type, assuring adequate vehicle design and maintenance, and providing sufficient space. Also important for assuring the welfare of the piglets during transport are sufficient rest time, appropriate access to food and water, defined measures for monitoring the animals during the trip, implementing means of disease control, and establishing the steps to be followed in case of an emergency.