Deficiencies in key vitamins and minerals including selenium, cobalt, copper, and vitamin B12 cause significant welfare harm in sheep, particularly in pregnant ewes and growing lambs on deficient pastures.
Mineral deficiency diseases in sheep cause suffering that can be entirely prevented with appropriate monitoring and supplementation. White muscle disease kills lambs that appeared healthy at birth — cardiac muscle damage causes sudden death, while skeletal muscle degeneration causes inability to stand, suckling failure, and starvation. Swayback from copper deficiency causes permanent neurological damage in affected lambs, causing uncoordinated movement and inability to nurse. These conditions are preventable: ewes supplemented with selenium and copper in late pregnancy raise lambs without deficiency signs. The management challenge is accurate diagnosis — clinical signs overlap between deficiency and other conditions, and soil testing, blood analysis, or liver mineral assay is needed to identify specific deficiencies before supplementation. The toxicity risk from copper means sheep welfare requires precision, not blanket supplementation. Farms in known deficiency areas should test ewes twice yearly and adjust supplementation accordingly.