Cobalt Deficiency in Cattle and Sheep: A Trace Mineral Welfare Issue

Cobalt deficiency — causing vitamin B12 deficiency — is a significant but often overlooked welfare problem in ruminants grazing cobalt-poor soils, leading to wasting, poor growth, and immune suppression.

Key Facts

Ruminants cannot directly use cobalt — rumen microbes convert dietary cobalt to vitamin B12 (cobalamin)
Cobalt deficiency results in vitamin B12 deficiency, impairing energy metabolism, red blood cell production, and immune function
Deficiency is most common on soils derived from granite, sandstone, and peat — geologically cobalt-poor parent material
Clinical signs include progressive weight loss, lethargy, anaemia, rough coat, watery eyes, and increased susceptibility to infections
Young, rapidly growing animals and pregnant or lactating females are most severely affected
Diagnosis involves blood cobalt or vitamin B12 measurements; pasture soil testing identifies at-risk areas
Treatment and prevention involve cobalt supplementation via drenching, boluses, fertiliser application, or injections

Welfare Considerations

Cobalt-deficient ruminants suffer a slow, debilitating decline that can be difficult to diagnose early. Affected animals show progressive wasting, weakness, and immune suppression — making them more vulnerable to parasites, respiratory disease, and other infections. The condition causes chronic, low-grade suffering that may persist for months before being identified. In severe deficiency, animals become profoundly anaemic and weak, unable to rise or feed normally. Because the signs are non-specific and develop slowly, many cases on cobalt-poor farms go unrecognised until multiple animals are affected. Regular soil testing and proactive supplementation on identified at-risk land is the most effective welfare and production intervention.

What You Can Do

Test pasture soils for cobalt status on farms in geologically at-risk areas
Implement routine cobalt supplementation programmes on confirmed deficient farms
Monitor at-risk animals — young stock, pregnant ewes — for early signs of wasting and poor condition
Work with your vet or agricultural consultant to establish blood monitoring for vitamin B12 status
Apply cobalt fertilisers to deficient pastures or use slow-release boluses in individual animals
Support agricultural extension services that help farmers identify and manage trace mineral deficiencies