With so many factors affecting the time taken to finish lambs for sale, such as parasites and disease, trace element status can occasionally be over looked. Trace elements are required by the ruminant and all play vital roles in their growth, development and productivity. If these vital trace elements are not supplied in sufficient quantities to meet the daily needs it will take longer to finish the lambs.
An adequate supply of cobalt is critical for lamb growth. After cobalt is consumed by the lamb it reaches the rumen where bacteria utilise the cobalt to produce Vitamin B12. Vitamin B12 is required for glucose synthesis and so is vital in achieving a good food conversion ratio.
Ruminants have no capacity to store cobalt and as a result lambs are very susceptible to Vitamin B12 deficiency, also known as pine, resulting in poor growth rates. In order to tackle a cobalt deficiency a continuous supply of cobalt must be utilised (such as a bolus).
Selenium is required to produce proteins which ensure the immune system functions properly so plays an important role in disease defence. A relationship exists between selenium and iodine and so they must always be considered together when investigating suspected deficiencies.
Iodine is a component of the thyroid hormones T3 and T4. The thyroid hormones regulate the rate of metabolism and control the rate of absorption of carbohydrate from the gastrointestinal tract therefore heavily contributing to a good food conversion ratio. The utilisation of iodine in the body depends on selenium.
Copper is a component of enzymes which play a role in energy metabolism and immunity. It is very important to remember that copper can be toxic to sheep and so copper supplements should only be given if a deficiency has been diagnosed. Blue faced Leicester and Texel sheep are particularly susceptible to copper toxicity.
Zinc is critically involved in cell replication and the development of cartilage and bone. Deficiency results in: reduced growth rates, abnormal skeletal formation, delayed sexual development, dermatitis and poor hoof health.
What approach should I take in my flock?
The key thing to remember is that trace element supplementation should always be targeted based on diagnosed deficiencies. You will only see a benefit to supplementing trace elements where a deficiency exists.
Forage is incredibly variable not only between fields on the same farm but from year to year. You must also take into account any other supplementation given such as concentrates, lick buckets, drenches etc and you can begin to see that it’s impossible to take a ‘one shoe fits all’ approach between different management systems.
You should work with your vet to determine which, if any, trace element imbalances are present. In addition to seeing no benefit to supplementation if no deficiencies exist- it may even harm lambs (copper and selenium can be toxic if over supplied).
From a commercial aspect there are two main considerations which justify the importance of investigation:
- You could be spending money on trace elements which are not required.
- You could be losing animal productivity to sub-clinical disease. Sub-clinical trace element deficiencies are not severe enough to be visualised by eye but will have an impact on the productivity of the animals. If you wait until the deficiency is so severe that clinical signs have appeared you will already be out of pocket.
Certain sheep breeds, Blue faced Leicesters and Texels in particular, are susceptible to copper toxicity. Selenium may also be toxic if over supplied. Please consult a vet or nutritionist to utilise diagnostics to establish the need prior to supplementation.
Date editorial prepared: February 2018
About the Author:
Rachel Mallet is a Veterinary Surgeon, who now works as a Professional Services Vet providing technical support to vets, SQPs and farmers in the UK. Rachel is passionate about animal health and about promoting best practice and preventative medicine amongst farmers.