WHAT IS COBALT?
An essential trace element that is ingested with the pasture and sometimes soil.
Sheep, in particular, require cobalt for the manufacture of Vitamin B12.
Cobalt is converted to Vitamin B12 in the rumen by rumen micro organisms.
Although referred to as cobalt deficiency it is the converted Vitamin B12 which is required by the animal not the cobalt itself.
THE MANUFACTURE, MOVEMENT & STORAGE OF VITAMIN B12 IN SHEEP
Cobalt is converted to Vitamin B12 by micro-organisms in the rumen.
Absorption of Vitamin B12 occurs primarily in the small intestine and is enhanced by slower rates of movement of material through the intestine.
Absorption is inhibited by damage to the walls of the small intestine, For example:caused by worms.
Vitamin B12 binds to blood and then is transported around the body.
The principle storage organ for Vitamin B12 is the liver. The animal draws on these reserves when required.
Pregnant ewes, adequate in Vitamin B12, will provide optimal amounts of Vitamin B12 to the foetus (developing lamb). This is important for early lamb growth and development. The colostrum contains some Vitamin B12 but is inadequate to provide any length of protection. Milk does not contain any significant quantities of Vitamin B12.
WHY DO SHEEP REQUIRE VITAMIN B12?
Vitamin B12 is essential for the growth of cells, energy production and wool production in sheep. Production losses, particularly in young sheep can be significant if Vitamin B12 levels are low.
CELL GROWTH AND MATURATION Young developing lambs, weaner sheep and pregnant or lactating ewes, have high requirements for Vitamin B12.
ENERGY PRODUCTION Propionic acid is a product of rumen fermentation. Vitamin B12 is essential in the conversion of propionic acid to succinate, then to glucose for energy. The main site of this conversion is in the liver.
WOOL PRODUCTION Vitamin B12 is required for the metabolism of methionine. Methionine is necessary for optimum growth and wool production.
COBALT DEFICIENCY AND HOW IT EFFECTS PRODUCTIVITY
Cobalt deficiency in sheep is associated with clinical signs described under many different names. More commonly, this disease is referred to as 'wasting' or 'coastal' disease indicating its prevalence in many coastal grazing areas of Australia.
An animal lacking in cobalt (Vitamin B12) shows similar signs to that of starvation.
The appetite is affected resulting in reduced feed intake causing:
decreased feed efficiency
Anaemia (low level of red blood cells), diarrhoea, scaly ears and weepy eyes are also clinical signs associated with a cobalt (Vitamin B12) deficiency.
PRODUCTIVITY & PROFITABILITY CAN BE SEVERELY EFFECTED THROUGH:
reduced growth rates, particularly in young animals
reduced wool cuts and wool quality
lower lambing percentages and low birth weights
high mortality rates in severe cases
TYPES OF COBALT DEFICIENCY
Severe cobalt deficiency is readily recognised by the clinical signs. These signs are not specific to cobalt deficiency and it is recommended that blood testing be carried out to confirm a deficiency. In severe cases, production losses can be significant and mortality rates can be high.
A marginal deficiency is of greatest concern because production losses may go unnoticed. A 'tail' in the flock is characteristic of this form of the deficiency, however reduced wool growth and reduced growth rates are less obvious in this situation.