Impact of nutrition on lameness and claw health in sows

Sow lameness is a multifactorial condition which is mostly related to disturbances in the processes of bone remodelling, cartilage metabolism, and horn production. This review discusses how bone, articular cartilage and horn are affected by diet composition, particularly vitamins and minerals.For bone remodelling, the role of carbohydrates, proteins, and amino acids is uncertain. The macrominerals Ca and P are extremely important, as is vitamin D. Magnesium may be as important as Ca and P. Dietary deficiencies or toxicities of microminerals Zn, Cu, Mn and F also play a detrimental role.Articular cartilage (AC) depends on a diffuse nutrient supply. An impaired proteoglycan (PG) and collagen synthesis are precursors for AC related disorders. The addition of amino acids, especially combined with microminerals such as Cu and Si, reduces the occurrence and severity of osteochondrosis, whereas convincing evidence for a specific role for macrominerals in AC metabolism is not found. The microminerals Zn, Mn, and Fe are involved to a lesser extent in these disorders.A diffuse nutrient supply is also essential for horn production. Especially sulphur-containing amino acids such as cysteine are important for keratinisation. The dietary availability and diffuse supply of macro- and microminerals directly and indirectly activate enzymes responsible for the development of keratin fibres and synthesis of an intercellular cementing substance. Biotin supplemented in combination with minerals also benefits horn production.In conclusion, nutrition is an important predisposing factor of sow lameness and influences bone, articular cartilage and horn quality. The regulatory mechanisms are complicated and not yet fully understood. Nutritional components often interact with each other, and must be balanced since both deficiency and excessive dietary intake may disturb these processes.