Welfare implications of invasive piglet husbandry procedures, methods of alleviation and alternatives: a review.

Iron administration, teeth clipping, tail docking and castration are common invasive husbandry procedures performed on piglets on commercial farms, generally within the first week of life. These procedures are performed to prevent potential health and welfare problems of piglets and/or the sow, or, with respect to castration, to enhance meat quality. The objectives of this review were firstly, to provide the rationale and scientific evidence for performing these procedures, secondly, to describe the welfare implications of these procedures, and lastly, to describe mitigation strategies or alternatives that can be used to eliminate or reduce the pain caused by these procedures. Administering supplementary iron is necessary to prevent anaemia in piglets and the procedure has a low welfare impact. The stated benefits of teeth clipping to prevent udder lesions do not appear to outweigh the risk from injury and infection in piglets following the procedure. Tail docking reduces the prevalence of tail biting, but does not eliminate this behaviour and the practice of tail docking can cause acute pain. Castration is primarily performed to reduce the occurrence of boar taint, but alternatives are now available that negate the need to perform this procedure. Teeth clipping, tail docking and castration all cause behavioural and physiological changes indicative of acute pain and can have potentially long-term negative consequences such as causing abscesses, lesions and the formation of neuromas. Therefore effective pain mitigation strategies (e.g. analgesia, local or general anaesthesia) that markedly alleviate the pain caused by these procedures are necessary to improve the welfare of piglets. Alternatively, if management practices are available that eliminate the need for performing these procedures altogether, then they should be adopted.