Cobalt is an essential mineral required by sheep. Cobalt has an important biological role as a constituent of vitamin B12 which is manufactured by micro-organisms in the first stomach (rumen). Cobalt deficiency (pine) occurs where there are low soil cobalt concentrations which may be further complicated by PGE which causes diarrhoea thereby interfering with the absorption of vitamin B12.

Clinical signs of cobalt deficiency are most commonly observed in weaned lambs at pasture during late summer and autumn. Signs include lethargy, reduced appetite, poor quality wool with an open fleece, small size and poor body condition despite adequate nutrition. There may be tear staining of the cheeks, and pale mucous membranes in the eyes develop after several months. Cobalt-deficient sheep may fail to respond well to vaccinations and be more susceptible to clostridial diseases (for example pulpy kidney) and pasteurellosis (pneumonia).

In severe cases of cobalt deficiency (referred to as ovine white liver syndrome) lambs present with nervous signs including depression, head pressing, and aimless wandering.

Cobalt deficiency is much less common in adults but is reported to cause reduced fertility and poor mothering ability but these signs may be more related to generalised low body condition scores.

CAUSE

• Disease of young stock occurring mostly in spring and early summer.
• Generally occurs on sandy coastal soils.
• Cobalt is utilised by sheep in the form of B12.

SYMPTOMS

• Sheep are ill-thrifty and anaemic.
• Sheep often have weepy eyes and photosensitisation.

DIAGNOSIS

• Blood testing for B12. Treatment
• Vitamin B12 injections.

PREVENTION

• In recognised cobalt deficient areas, lambs should be given an injection of vitamin B12 at marking and a second dose two months later (often in conjunction with a clostridial vaccine).
• Weaners remaining on cobalt deficient pastures can be given a cobalt bullet at 3 months of age.