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Iodine Deficiency in Cattle: Goitre and Welfare

Iodine deficiency causes goitre and reproductive problems in cattle. This guide covers welfare impacts and prevention through supplementation.

Key Facts

Iodine is essential for thyroid hormone production affecting growth and metabolism
Deficiency causes goitre (enlarged thyroid gland) particularly visible in newborn calves
Goitrous calves may be weak at birth and have impaired temperature regulation
Reproductive failure including stillbirths and weak calves occurs in iodine-deficient herds
Certain plants (brassicas, clover) contain goitrogens interfering with iodine utilisation
UK soils are often iodine-deficient requiring supplementation

Welfare Considerations and Management

Iodine deficiency prevention requires supplementation programmes tailored to local soil and feed conditions. Iodine supplementation of cattle can be achieved through mineral blocks, iodised salt, or boluses. Care must be taken not to oversupplement as iodine toxicity causes similar clinical signs to deficiency. Feeds high in goitrogens (brassica crops) increase iodine requirements. Monitoring of newborn calf thyroid size identifies herd-level deficiency.

What You Can Do

Test soil and blood iodine levels before implementing supplementation
Use iodised mineral supplements for cattle grazing iodine-deficient areas
Monitor newborn calf thyroid gland size as an indicator of herd iodine status
Increase iodine supplementation for cattle receiving high brassica diets