Trace-element deficiency in lambs is all too often attributed to a natural post-weaning check. The result is fire-brigade tactics in an attempt to correct the problem.
But according to Cumbria vet Matt Colston, trace-element deficiencies could be more widespread this spring as sheep producers try to reduce feed costs.
“Many lambs suffer a post-weaning check, and it’s something many producers accept as the norm when it could be avoided.
“Blood-sampling a bunch of lambs at weaning – at barely the cost of one prime lamb – will identify any trace-element deficiencies, which can then be treated at just a few pence a head,” says Mr Colston of Frame, Swift and Partners, Penrith, who is also a Moredun Institute board member.
Lambs looking stale and those that lose their bloom when switched from a milk-based diet to one of grass could be suffering from cobalt or selenium deficiencies, or even a shortage of iodine, which can be critical to lamb thrift.
“A marginal selenium deficiency, underpinned by a critical iodine deficiency, means lambs are unable to use any of the selenium in the diet. If only treated with selenium these lambs will show a temporary improvement in thriftiness, but it will be short-lived,” says Mr Colston.
“Suckling lambs can cope with these deficiencies because milk is coming through from ewes and into the lamb’s abomasum.
“Lambs function at this stage in their life as a ‘simple stomach’ animal and not a ruminant. Once lambs are weaned their digestion becomes that of a ruminant.
“When there are trace-element deficiencies in the diet this is when they show up. Even if ewes are being cut back a little on feed this year it will not have a big impact on lambs’ trace-element profile, provided ewes are still giving enough milk.
“If a feed cut leads to a lower milk yield in ewes, lambs may wean themselves and trace-element deficiencies could be identified before lambs are taken off ewes.
“To get the best out of lambs they should be watched closely in the weeks prior to weaning. Worm control should be more hands-on. Don’t just worm lambs routinely, but take faecal egg counts to enable worming to be more effective and to save on drench.
“The results of using wormers containing cobalt and selenium can sometimes confuse what’s really happening. When lambs are seen to improve following treatment with this type of combined drench, the assumption is it was worms causing the problem
“Quite often there were no worms present, but the benefit has been through the trace-element treatment. That can mean money wasted on wormer and a hit and miss approach to dealing with a trace element deficiency when a simple blood sample session would have given a precise profile to work with and ensure growth rates were maintained.”