Cobalt deficiency is one area where a high percentage of sheep farms face challenges.
Issues typically start to emerge from July onwards, but this can differ significantly, depending on the mineral status on the farm, with some farms finding problems more prevalent in August and leading into September.
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.
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.
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 option 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.