News & Advice

Cobalt Deficiency

Sep 4, 2018 | Dry stock, Dry stock animal health & welfare, Sheep

About 13% of pastures in New Zealand will not provide an adequate Cobalt intake for lambs which are the most sensitive to Cobalt deficiency. Regular use of Cobalt in New Zealand has meant disappearance of clinical (but not sub-clinical!) deficiency in cattle and mature sheep but not in lambs.
Cobalt is required to create vitamin B12, which is why there is often confusion about which is the necessary thing to supplement. B12 injections, oral Cobalt bullets or top dressing with Cobalt sulphate will prevent deficiency.

Function of cobalt

  • Cobalt is essential for the synthesis of vitamin B12 by rumen micro-organisms
  • Vitamin B12 is important for energy and protein metabolism
  • Maintains the integrity of the immune system

Clinical signs of cobalt deficiency

  • Poor growth rates
  • Loss of appetite
  • Watery eye discharge
  • Increased lamb death rates at lambing time

Cobalt deficiency diagnosis

To diagnose Cobalt deficiency, ideally vitamin B12 concentrations from 10 blood (serum) samples per group of lamb is required. The samples are graded as either deficient, marginal, or adequate.
Sheep grazing pasture with Cobalt concentrations of <0.08 mg/kg DM will become Cobalt deficient. Note that soil contamination can increase “pasture” Cobalt concentrations and, therefore, tissue vitamin B12 concentrations give a more reliable assessment of lamb B12 status.

Cobalt deficiency prevention

Options for preventing deficiency include:

  • Treating lambs with vitamin B12 as an injection given subcutaneously in the neck region once at docking. The products available are Smartshot which lasts three to four months or up to 8 months depending on dose amount, or Prolaject B12 which lasts four to six weeks.
  • Treating the ewes during late gestation with Prolaject gives a period of three to four weeks protection to their lambs, while Smartshot if given at mating lasts 10 months in the ewe and protects the lambs until a month old.
  • Topdressing with Cobalt sulphate annually in the spring; please note that this approach is unsatisfactory on some soils because high manganese (Mn) levels can interfere with Co uptake by plants. From a management point of view, pasture must not be grazed for at least four weeks to allow the Co to be ‘washed’ into the soil and taken up by the pasture.
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