Blood sampling suggests common cause to West Cumbria mineral deficiencies

At a meeting of the Allerdale Livestock Group in October, farmers heard how the results of a trial undertaken on four Lake District farms into blood profiling of sheep for mineral deficiencies panned out.

Funded by the Livestock Programme and carried out by Millcroft Vets, the trial was undertaken by members of Allerdale Livestock Group and facilitated by Cumbria Farmer Network. 

James Frayne from Millcroft Vets explained how the trial was conducted and discussed the results.  Blood samples were taken from six ewes from four farms in different Lake District valleys of West Cumbria with the samples being tested for copper and selenium.

He explained the importance of trace elements for a healthy flock with cobalt deficiency causing problems in growing lambs; selenium deficiency causing white muscle disease (with stiff, weak lambs and poor flock growth and fertility); and copper deficiency causing swayback in lambs, steely wool and poor sheep fertility.

Thiomolybdate toxicity in the soil binds copper up by other elements, including sulphur and iron, making copper unattainable to ruminant animals as it passes straight through the rumen. This is more common on the fertilized lowlands, while fell sheep are often less prone to copper deficiency.

Cobalt deficiency is known as “pine”, a disease of weaned lambs which appear lethargic with poor wool and is often linked with worm infestation. Food moves through the gut too fast to be absorbed, thus cobalt is often given as part of a worming drench.

James Frayne then went on to discuss the individual findings on the farms tested:-

St John’s in the Vale:

Selenium levels were normal but sheep showed some evidence of long term exposure to thiomolybdate with copper bound up (there had been no copper given within 4-6 weeks of testing).

Borrowdale:

Selenium levels were high (the sheep had been drenched in Summer).  Strong evidence of thiomolybdate toxicity.

Lorton:

Selenium levels high. Evidence of thiomolybdate toxicity.

Calderbridge:

Very low selenium.  The least evidence here of thiomolybdate toxicity, but strong evidence of primary copper deficiency on the farm. The farmer, Kevin Holliday had soil samples taken earlier in the year and the blood levels supported these findings, with a suggestion that these levels would affect fertility.

James Frayne then went on to discuss feeding supplements to overcome mineral deficiencies including:-

Drenches containing cobalt and selenium, but the effects are short term.

Copper is available in gelatine capsules but doesn't give a long duration of cover.

Boluses are the best for sustained release and, if inserted before tupping, will last through pregnancy and lactation ensuring copper in the womb and strong healthy lambs at birth.  It is important that the boluses are kept at room temperature for 24 hours before treatment as cold boluses can promote regurgitation.

The VLA website warns that copper toxicity is as common as copper deficiency, thus only one supplement should be given of copper with no other additives given containing copper.  This is particularly important for Texel breeds which are very prone to copper poisoning.

Three of the farmers tested are now considering an on-farm trial, inserting boluses 2 – 3 weeks before tupping in a sample of their sheep flock, marking these and noting results on scanning and after lambing.

For more information about the trial, please contact Veronica Waller, The Farmer Network NW Livestock Programme Manager on 01524 782488.

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