Vitamin B12 is an essential trace element for growth in young lambs.
Lambs low in vitamin B12 can have reduced growth rates, ill-thrift, dull coats, and reduced appetite. Although they may not appear clinically unwell, these lambs often fail to reach their growth targets, resulting in lighter weights and longer finishing times.
Severe B12 deficiency (not often seen in our modern farming systems) results in runty lambs in extremely poor condition, despite good feed levels.
In simple steps, the cobalt-vitamin B12 relationship can be described as:
Cobalt, a micromineral found naturally in soil (or put on pasture), is taken up by plants.
Sheep consume the plants and therefore ingest cobalt.
Rumen microbes convert the ingested cobalt into vitamin B12.
B12 supports energy metabolism, growth and appetite. Deficiencies can lead to poor growth rates.
Pasture type and quality have a marked affect on the amount of cobalt available for lambs, with pastures high in legumes often containing superior levels of cobalt.
Clinically, we often see issues with high parasite burdens and low B12 liver stores going hand in hand – they seem to predispose each to the other.
Plus, the growing awareness of parasite resistance, and the resulting changes in parasite management, may mean you’re giving your lambs different amounts of minerals than you used to. You may be using a novel drench that doesn’t contain minerals, or adopting grazing strategies designed to reduce drench use.
Farms that are not hitting their growth rates, or have shifted to systems with less mineral oral supplementation, should be aware of the importance of B12 in lambs and consider appropriate supplementation to meet requirements.
Long-acting injectable B12 (such as SmartShot) provides six months of increased and adequately maintained B12 levels for lambs. Interestingly, studies have shown that a single long-acting injection given pre-mating in ewes can provide their lambs with adequate B12 levels until one month of age.
Long-acting injectables reduce labour and time, as they replace the need for multiple short-acting injections. However, short-acting B12 injectables are still a good option, and can be given monthly to help maintain levels.
In short, changes in management and drenching practices may mean it’s time to review your B12 supplementation.
For further discussion about your lambs’ mineral status and growth, have a chat with your KeyVet.
