Fearfulness

Fear is the reaction to a threatening event. It is a natural and adaptive behaviour which allows animals to avoid a potential danger. In the production environment, avoidance possibilities are limited or even inexistent in many situations. Thus exposing pigs repeatedly to frightening situations may lead to chronic stress, which is detrimental to health, welfare, reproduction and productivity.
When the threat is perceived as low, pigs rather express vigilance reactions toward the potential danger like immobility, observation and opening of the ears. When the threat is perceived as high, pigs express avoidance reactions like moving away or trying to escape, or even defensive reactions. Escape attempts and defensive reactions can be dangerous for pigs, as well as for human caretakers safety, as both can get injured. One may not expect the same fear reaction from all pigs, as fearfulness varies among individuals. But the reaction of one fearful pig may spread to the group through behavioural signs, odours or stress vocalizations.
Several situations may be frightening for pigs. Although pigs are curious in general, unexpected or novel situations can induce fear reactions: i.e. a new environment (pen or room, novel object, food or smell) or a new situation (unacquainted pig or human, new handling procedure). For example pigs show fear during many handling procedures such as castration, tail docking, tooth resection, vaccination, or transportation because these situations are unknown, unexpected and intense, and induce noise, pigs’ vocalizations and agitation and sometimes pain. Isolation is especially fear eliciting because pigs are social animals.
To prevent pigs from feeling fear, handlers should reduce sources of fear as much as possible, or try to make them less new or unexpected. For instance, letting piglets run in corridors of the room may help them to be less fearful when they will be moved at weaning or to the fattening pens. Treating pigs gently during routine handling is recommended; it not only decreases fear of humans, but it may help them cope better with novel environments and situations.