Selenium deficiency in cattle causes white muscle disease in calves and reduced immunity and reproductive performance in cows, with significant welfare consequences in affected herds.
Selenium-deficient calves with white muscle disease experience severe welfare compromise from muscle degeneration. The inability to stand or nurse causes immediate nutritional deprivation and exposure to cold in neonatal calves. Cardiac white muscle disease causes sudden heart failure that is acutely distressing. Less severe selenium deficiency causes chronic impairment of immune function, making cattle more susceptible to infectious disease and its associated welfare harms. Reproductive failure in selenium-deficient cows causes poor pregnancy outcomes and weak neonates that themselves face welfare challenges. Retained placentas, which are more common in selenium-deficient herds, cause uterine infection that causes significant pain and systemic illness.