Cobalt deficiency

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 in to August and September.

The secret to keeping on top of issues is to be on guard for signs of a deficiency emerging, and pre-empt issues before they emerge. Characteristic signs start with lambs performing below target and, in some cases, an early indicator is the skin on lamb’s ears becoming scaly or scabby, with skin flaking away. Lambs suffering from an acute deficiency can start to lose condition and go dry in the wool, despite being 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.

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.

Grass management

The persistent inclement weather in recent weeks is proving increasingly challenging. As detailed in this week’s sheep feature on page 31, lamb performance is struggling on many farms, with some of the farms in the Teagasc BETTER Farm Sheep Programme now implementing finishing groups, whereby heavier lambs are being segregated for supplementation to aid finishing.

The practice of reviewing lamb performance and implementing a plan on how best to bring lambs to market is one that should be adopted by all farmers. The year is pushing on and the focus will quickly turn to building grass supplies. For example, the target at present is to have 15 to 17 days grazing ahead of stock. This will increase to 20 days towards the end of August. If finishing of lambs is delayed and there are more mouths to feed at a critical time, then this could limit the potential to build grass supplies. A factor which caught many flocks in 2022 was lower levels of fertiliser being applied in the second half of the year due to higher costs.

It is advisable to also review your fertiliser programme and put a plan in place. The earlier fertiliser is applied, the greater the response will be in general with the seasonal decline in grass growth rates intensifying as you progress in to August. Where the focus in recent years has been on nitrogen fertiliser over compound fertiliser, it is important to address any potential nutrient deficiencies and, in particular, replenish nutrients in swards where there has been a significant off-take for forage.

SIS questions

Last week’s questions and answers on the genotyped ram action in the Sheep Improvement Scheme is generating good feedback. There have been a number of questions received since then and the answers to these are printed on the opposite page. You can continue to send any questions to farmtechtalks@farmersjournal.ie, or text / WhatsApp to 086-8366465.