Reports this year regarding the incidence of cobalt deficiency have been variable.

Some farmers reported issues earlier than normal, some of which began during the prolonged dry spell, while others have seen issues emerge as normal in recent weeks.

The highest risk period is typically July and August, but the timing and severity of the challenge can vary greatly depending on the mineral status of the farm.

Some farms which always face a challenge often do not see issues emerge until well into August and September.

Characteristic signs

The secret to keeping on top of issues is to be on guard for signs of a deficiency emerging and preempt issues before they emerge.

Characteristic signs start with lambs performing below target and, in some cases, an early indicator is the skin on lambs' ears becoming scaly or scabby, with skin flaking away.

A lamb with characteristic signs of cobalt deficiency on the edges of its ears.

Lambs suffering from an acute deficiency can start to lose condition and start going dry in the wool despite on a relatively good level of nutrition, while tell-tale signs of more advanced problems are lambs starting to pine away.

Lambs typically require about 1mg cobalt per head per day and since they do not store cobalt, regular supplementation is warranted during high-risk periods.

Where administering an oral drench, the advice is to administer every two or three weeks.

Treatment is seen to last for two weeks, but there will not typically be a major hit in performance where treatment is carried out every three weeks.

Treatment options

Other options include administering boluses or feeding meal with an adequate mineral inclusion level.

Adding cobalt to water may also be an option, but this is less reliable unless you are sure lambs will be consuming enough water.

If you are in doubt about problems on your farm, samples can be taken to identify if there are underlying issues, while a simple way of exploring is to randomly split lambs in a batch, treat 50% and monitor subsequent performance.

Environmental conditions need to be similar to get an accurate reflection on lamb performance without any bias, ie there is little point in treating a batch of lambs and leaving another batch untreated that are grazing as a separate group.

Ewes generally do not have any issues with cobalt deficiency.