Behavioural characteristics of entire males are influenced by sexual hormones and include an increased tendency for activity, aggression and sexual behaviours such as mounting. It is important to focus on how to minimize negative welfare consequences of these behaviours during raising. The most important factors seem to ensure stable social relationships, enrichment of pen environments to satisfy the increased activity levels, and to create possibilities for avoiding agonistic attacks (see ‘Show more’).
Guidance
EURCAW-Pigs’ “Review on keeping entire male pigs” addresses the increased tendency for aggression and sexual behaviour in entire males and identifies four key areas in successful housing of entire males:
Space allowance and group size
An increased space allowance for entire males does not reduce the level of aggression or sexual behaviour per se. However, space allowance becomes particularly important when it allows animals to avoid agonistic encounters and mounting and thereby reduces the risk for injuries.
Feeding strategies
Studies indicate that feeding by a long trough, ad libitum feeding, feeding wet by-products, diets with a high level of amino acids, a good hygiene of the feeding and drinking place and sufficient water supply of the drinking system are associated with less sexual and aggressive behaviour and less skin lesions.
Enrichment of environment
Environmental enrichment, encompassing factors such as increased space allowance, access to straw bedding, provision of roughage, or outdoor areas, may not necessarily reduce agonistic interactions. However, enrichment occupies and distracts the animals from negative encounters. Moreover, bedding decreases the slipperiness of floors. Consequently, the risk for negative welfare effects such as skin lesions and lameness is lower.
Group composition
A stable group composition is important when keeping entire males. However, rearing of litters without any mixing is difficult to implement in current housing systems. Mixing entire males with females is beneficial for the males, although from the point of view of the females, single-sex housing would be preferred.
Source photo: ©LSZ Boxberg
