Selenium deficiency in cattle causes white muscle disease in calves and reproductive failure in cows, and is a preventable welfare problem in herds on selenium-deficient soils without appropriate supplementation programmes.
White muscle disease causes profound suffering in neonatal calves: unable to stand or suckle, they rapidly become hypothermic, starve, and die without intensive intervention. Even calves that survive severe episodes may have permanent muscle damage affecting growth and productivity. Preventive supplementation of cows in the last trimester of pregnancy, or treatment of newborn calves in deficient herds, eliminates this disease. The welfare failure of allowing white muscle disease in a herd where the cause is known is significant — it represents a preventable source of acute suffering. Regular soil and forage selenium testing allows farmers to calibrate supplementation precisely and avoid both deficiency and toxicity.