Treatment and prevention of lameness with special emphasis on claw disorders in group-housed sows

Since 2013, group-housing of gestating sows is obligatory in all member states of the European Union. However, the alteration implemented to enhance sows' well-being harms other welfare aspects as claw lesions are more prevalent in group-housed sows compared to individually stalled sows. To avoid unnecessary distress and associated financial losses, early treatment of claw disorders is necessary. Non-steroidal anti-inflammatory drugs are important to alleviate pain. The decision between antibiotic therapy, claw trimming, amputation or foot bath will depend on the diagnosed claw disorder. Often, claw lesions are detected in a severe or chronic stage when the animal is clearly lame. Treatment at this time is frequently unrewarding. As a consequence, prevention of claw lesions has a merit. Factors affecting the prevalence and severity of claw lesions and infections are related to claw conformation, housing, nutrition and management. They are the key to a proper preventive strategy. Although group-housing of sows on deep litter, based on straw, would be the best solution for intensively kept sows, most herds use a partly slatted, concrete floor without bedding for practical reasons. Keeping the floor dry and clean and providing good floor quality (avoid protruding sharp objects, rough or slippery concrete, crumbled slat edges and enlarged gap width) may diminish development of claw lesions and claw infections. Supplementation of vitamins and minerals above the requirement level can be applied. Nonetheless, there is a lack of recent scientific literature on group-housed sows to clearly support or refute this strategy. Due to its relevant genetic background and the impact on sow culling, both claw size and hoof growth could be appealing selection criteria for prevention of claw lesions and improvement of sow longevity. Regular claw trimming is not recommended as a prophylactic measure. Foot baths may have potential as part of a preventive strategy, but their use in group-housed sows needs further research. In general, it can be concluded that preventive measures can be implemented to reduce the incidence and severity of claw lesions in group-housed sows. Yet, more research is needed, specifically studies investigating requirements for nutrients for optimum foot health. A clear definition of the supplementation level and standardization with respect to duration of the trial and housing and management, which may also influence claw health, may contribute to more consistent and comparable results.