Livestock

Selenium Deficiency and Toxicity in Cattle: Welfare Management

How selenium status affects cattle welfare and how supplementation must be precisely managed.

Key Facts

Selenium deficiency causes white muscle disease — potentially fatal in young calves
The margin between deficiency and toxicity is narrow — over-supplementation is dangerous
Selenium toxicity (selenosis) causes hair loss, hoof abnormalities, and reproductive failure
Blood and soil testing guide appropriate supplementation strategies

Welfare Considerations

Selenium deficiency causes acute welfare harm in calves — white muscle disease produces sudden onset weakness, heart failure, and death. Selenium toxicity at the other extreme causes chronic welfare deterioration through hair and hoof changes. Welfare-focused management uses blood testing to establish status before supplementation and chooses appropriate supplement concentrations and routes based on clinical evidence.

What You Can Do

Test blood selenium levels before implementing supplementation programmes
Use slow-release boluses or dietary supplementation rather than injectable selenium without vet advice
Never supplement with selenium products without testing — toxicity is irreversible