Ark Veterinary Centre

Cobolt in Lambs

May 28, 2020

Lambs start to need more cobalt as they change from a predominantly milk diet to grass.

All ruminants require cobalt in their diets for the synthesis of vitamin B12, which is essential for energy metabolism and the production of red blood cells. Cobalt deficiency in lambs causes reduced appetite and ill thrift. If the deficiency is severe, lambs start to fade away, become extremely weak and die. Ruminants are only able to store small amounts of vitamin B12, so cobalt needs to be regularly available. This makes supplementation more difficult than with some of the other trace elements where stores are greater. If extra cobalt is given by drench, this should ideally be done every week, although every 2 to 3 week will usually suffice. Rumen boluses release a small amount every day but our experiences to date have shown that they are not always effective in preventing cobalt deficiency in lambs. Some boluses are probably better than others, but there’s an inherent difficulty in producing boluses that are small enough to put in a lamb but big enough to stay in the rumen as the lambs grow. Injecting with vitamin B12 is another option, but once again, this needs to be done every few weeks and repeatedly injecting fat lambs risks damaging the carcase. A New Zealand product called Smartshot B12 provides up to 6 months supply of vitamin B12 from a single injection. Smartshot is now available in the UK and we can source it if we apply for a special license. We feel that Smartshot B12 might be useful for longer keep lambs, especially when it’s difficult to gather lambs on a regular basis. The smallest pack size is 500ml, with young lambs requiring 1ml – so the product is only suitable for larger farms. 

Please contact the practice if you are interested in trying this. If lambs aren’t treated until weaning time, the dose increases to 2ml per lamb.