Environmental enrichment to improve behaviour in farm animals.

Abstract Domestic animals under close confinement conditions frequently display abnormal behaviour, particularly if they are unable to escape from, or adapt to this situation. With the increased interest in domestic farm animal welfare from both the political and societal agendas, environmental enrichment (EE) is becoming an interesting solution, offering an alternative not only to optimize the welfare of the animals but to improve the animals' performance. In general, the development of more intensive production systems and specialized techniques has provided benefits in terms of productivity, but at the expense of the behavioural needs and welfare of kept animals. In intensive farming, welfare concerns are still often related to barren environments and crowded conditions. Producers need to balance the requirements to improve welfare conditions on the farm with practical considerations. This paper provides a review of the scientific literature, focusing on recent advances on the welfare-relevant consequences of EE on harmful social behaviours due to intensively farmed confinement in pigs, laying hens and dairy calves, including a discussion with regard to their relevance and suitability.