Published in the Jameson Journal, June 2026

Cobalt is one of those trace elements that is often overlooked until livestock performance suddenly drops off. Yet for sheep and cattle, it plays a hugely important role in growth, thrive, immunity and overall productivity.

Cobalt itself is not directly used by the animal, but it is essential for the production of vitamin B12 by the rumen microbes. Without enough cobalt in the diet, animals cannot produce adequate vitamin B12, which is vital for energy metabolism, appetite and growth. This is why cobalt deficiency, often referred to as pine, can have such a dramatic effect on lamb performance.

We are seeing more issues with cobalt deficiency on farms for several reasons.

• Wetter seasons, faster growing grass, increased stocking rates and higher lamb performance targets can all increase demand and dilute trace elements within forage.
• Many marginal upland and hill soils are naturally low in cobalt, but even some traditionally safe areas are now showing deficiencies, particularly where grazing pressure is high or parasitic burdens are present.

Parasitic gastroenteritis (PGE) can further complicate the issue. Worm challenges can cause scour and gut irritation, reducing vitamin B12 absorption and utilisation. Also, there is often a significant overlap between chronic parasitism and cobalt deficiency, making diagnosis difficult. Farmers frequently treat lambs for worms only to find they still fail to thrive afterwards.

Typical signs of cobalt deficiency include:

• Poor growth rates, reduced appetite, lethargy, open fleeces, tear staining and poor body condition despite adequate grazing.
• Lambs often have a fixed stare and fail to match the rest of the group.
• In more severe cases, immunity can be compromised, increasing susceptibility to clostridial disease and pneumonia.

Products from companies such as Animax and Agrimin have helped farmers tackle deficiencies more effectively through targeted supplementation systems, and at W.E. Jameson, we have several options, including drenches, boluses and mineral buckets.

Treatment options vary depending on the severity and stage of the deficiency, and we are always available to talk through the best option. In clinically affected lambs, a drench like Jameson Immu-Gain, which contains B12 and cobalt, can provide the quickest response. Ongoing management may then involve monthly cobalt drenches, cobalt boluses or well-formulated mineral buckets.

Boluses can work well where supplementation is needed over a longer period, while buckets offer a practical way to support growing lambs and breeding stock alongside other key minerals and vitamins.

Importantly, cobalt supplementation is relatively inexpensive compared with the cost of poor growth rates and delayed finishing.

• A lamb held back by deficiency can easily cost £10-15 in lost performance, while supplementation costs only pennies.
• If lambs are not thriving despite good grass and worming, cobalt should always be on the list of possible causes.

For help and advice on identifying and managing cobalt deficiency in your flock, call 01765 689666