Ruminants require cobalt in their diet as rumen microbes use this trace element to synthesise Vitamin B12. Vitamin B12 is essential for energy metabolism and deficiency can result in sub-optimal growth rates in lambs. Andy Henderson explains this a little bit more.
Deficiency can be compounded by other risk factors such as heavy worm burdens and antagonism from soils high in iron and manganese. This reduces absorption and creates a deficiency as stores present in the liver and kidneys become depleted.
Milk will provide an early source of Vitamin B12 as long as the ewes diet contains adequate levels of cobalt. Though as forage intake increases from 6 – 8 weeks of age, often being 100% of the diet and as parasite challenge increases intake of cobalt can become a common issue in fast-growing lambs in the peri and post weaned period.
Target growth rates of greater than 250g/day should be achieved to ensure eight week & weaning weights are on target and to achieve a key measure of performance with 50% of the lamb crop sold by 16 weeks.
Estimated production losses associated with even small reductions in growth rates and delays to sale are estimated at £10 – 15 per lamb, which represents a significant hit on margin with prime lamb averaging ca. £80 at the moment.
If you have a high percentage of lambs not reaching target growth rates or exhibiting clinical signs of deficiency then further investigation is warranted.
Blood sampling 6-10 lambs is the gold standard to determine Vitamin B12 levels and could be carried out at the same time as part of our Faecal Egg Counting Service provided by our VetTech team.
Blood sampling should be performed as soon as possible post gather as levels rise quickly once off pasture. We can also assess other trace elements at the same time such as copper, selenium and iodine which can also limit performance.
Options for supplementation:
Short-acting (ca. 3 – 4 weeks)
Cheap – 2p per lamb per month
Longer-acting (up to 6 months)
Risk of bolus gun injury
Long-acting (up to 6 months)
- Pasture dressing
May not be cost-effective