COBALT DEFICIENCY IN GROWING LAMBS

Last year we found multiple farms having poor growth rates in their lambs over the late summer months. Through investigation with forage analysis and blood sampling, we found many were deficient in cobalt; an essential trace element required for the formation of vitamin B12 by ruminal microorganisms. Vitamin B12 is important for the formation of energy from ruminal fermentation.

Cobalt deficiency (“pine”) may be seen in growing lambs put onto cobalt-deficient pastures after weaning.

Clinical signs include:

• Lethargy
• Pica
• Weakness
• Poor appetite and body condition, despite adequate diet
• Poor feed conversion efficiency and growth rate
• Pale mucous membranes
• Reduced wool quality

Diagnosis is based on clinical signs supported by low blood or liver B12 concentrations. Cobalt deficiency should be considered alongside parasitic gastroenteritis and coccidiosis in groups of lambs which are not thriving as expected as heavy parasite burdens interfere with the absorption of vitamin B12.

Cobalt can be supplemented via an oral drench, injection or slow-release bolus. Oral drenches are the cheapest and easiest way to supplement, however as cobalt is not stored in the liver, the benefits of oral drenches are questioned. The supplementation will last for 2-3 days which may not be sufficient enough, therefore will require many repeats throughout the season. SMARTSHOT®B12 is a long-acting injection which maintains adequate levels for 6 months, so avoids the need for repeated handling and drenching. 0.5ml for fattening lambs and 1ml for replacements may be given by subcutaneous or intramuscular injection in the neck from 3 weeks of age. Although slightly more expensive, boluses provide a much longer period of cover. They provide the nutrients on a slow-release basis at a consistent rate. One bolus could provide cover for the whole season!

Be aware though as many drenches & boluses come as a mixed mineral formulation, there is a risk for over-supplementation of some trace elements. With most, this won’t cause an issue as the excess minerals will pass through the gut and out the back end, however, be cautious with copper as too much can be toxic!!