Sheep farmers are being urged to review nutritional support ahead of weaning, as surveillance data highlights a seasonal spike in cobalt deficiency cases between July and September.

Data from the Animal and Plant Health Agency (APHA) and Scotland’s Rural College (SRUC) shows cobalt deficiency ranked as the third most common diagnosis in sheep and lambs during this period between 2016 and 2025.

Cobalt is needed by rumen microbes to produce vitamin B12, which supports appetite, energy metabolism, growth and immunity. A deficiency can result in symptoms collectively known as ‘pine’, often seen as lambs losing condition, going dull in the fleece and, in some cases, showing signs of anaemia. In severe cases, it can be linked to ovine white liver syndrome.

But while cobalt deficiency is in the spotlight, Fevara trade account manager Aled Evans-Hughes says the data should prompt farmers to review the wider diet.

“Cobalt deficiency is one of many issues farmers need to be aware of, and poor performance is rarely caused by one thing alone,” says Mr Evans-Hughes.

“At weaning, lambs are already under pressure, so any gap in the diet, from energy and protein to minerals and trace elements, can quickly affect appetite, growth and finishing time.”

The post-weaning period is a key risk point, as lambs move away from milk and become more reliant on grass and forage. Mr Evans-Hughes says the financial impact can be significant if lambs lose momentum at this stage so identifying weak points early is essential.

He adds: “When we’ve seen cobalt or B12 issues on our farm, the lambs haven’t necessarily fallen apart overnight.

“It’s often more subtle; they don’t thrive as well and take longer to finish, which soon starts to affect returns.”

Where lambs are failing to thrive despite adequate grazing or recent worming, Mr Evans-Hughes advises farmers to consult their vet or animal health adviser and consider testing alongside a review of nutrition and parasite control.

In some areas, farmers may already know they are farming in a region prone to a particular trace element or mineral deficiency.

This knowledge, combined with flock history, soil and forage analysis and veterinary advice, can help producers put support in place before deficiencies show as lost growth or poor condition.

Weather and soil conditions add another layer of risk, with rainfall increasing leaching, drought limiting grass growth, and sub-optimal soil pH or recent liming all influencing trace element interaction and availability. Mr Evans-Hughes says parasites should also be investigated, as worms and cobalt deficiency can go hand-in-hand, affecting nutrient uptake and immunity.

“You expect lambs to take a check at weaning, but if a nutritional gap means lambs take an extra week or two to finish, that can erode margins meaning more input costs and potentially selling into a more crowded, competitive market,” he says.

“It comes back to selling more kilos of lamb as efficiently as possible.”

Mr Evans-Hughes says the right intervention depends on the severity of the issue and how long support is needed.

“Drenches and injections give a sharp hit but are usually short-lived. Boluses provide longer-term support, focusing on gradual release of key trace elements - but must be appropriate for the animal’s size,” he adds.

“Offering buckets and licks can provide broader, more ongoing support where multiple nutritional gaps may be affecting performance.”

Licks such as Crystalyx Extra High Energy can be used as part of this balanced nutrition approach, providing energy and protein alongside a full complement of minerals, trace elements and vitamins to stimulate the rumen and forage utilisation while lambs transition from milk to grass.

“The aim is to keep lambs thriving and help them make the most of what’s in front of them,” adds Mr Evans-Hughes.

“Cobalt may be the issue highlighted by the data, but it should prompt farmers to look more widely at nutrition, minerals and the other pressures affecting lamb performance before growth is lost.”