Trace element nutrition for growing lambs

Whether lambs are destined to be breeding or fat stock, getting the balance and level of trace elements right in their diet is essential for efficient production, writes Sharon Cooksey, BVSc., MBA, MRCVS | Professional Services Vet UK, Bimeda.
By The Newsroom
Published 8th Jun 2021, 08:21 BST

Deficiencies in trace elements can limit or restrict normal development and growth.

Trace elements are sometimes called ‘micro-minerals’ as they are essential in very small amounts. The most common trace elements to be considered commercially important for growing lambs are copper, cobalt, selenium, iodine and zinc. Here we explore the role of these important trace elements in the health of growing lambs.

Copper functions as an enzyme activator and enzyme constituent in a broad range of enzymes which are vital to immune function, cell-building processes, bone and collagen development, red blood cell formation and melanin pigment (colour).

It is very important to remember that copper can be highly toxic to sheep and so supplementation should only be considered where a deficiency is diagnosed. For example, breeds such as Bluefaced Leicester, Zwartble and Texel sheep are particularly susceptible to copper toxicity.

Cobalt is required for the synthesis of vitamin B12, which is essential for energy metabolism and the production of red blood cells. B12, and so cobalt, are also essential for DNA synthesis and cell division which are both imperative for growth; also to the normal functioning of nerve tissue. Ruminants are particularly sensitive to deficiency of B12 and they have very little capacity to store cobalt, so a deficiency significantly affects the production of B12 very quickly (within days).

Selenium is required for normal growth and is essential for immune function, muscle and red blood cell integrity.

Iodine is a component of thyroid hormones which regulate the rate of metabolism and control the rate of absorption of carbohydrate from the gastrointestinal tract. Iodine is therefore central to a good food conversion ratio. The utilisation of iodine in the body also depends on selenium, as selenium is critical to thyroid hormone synthesis and activation.

Zinc operates as a co-factor in around 300 enzymes which are involved in protein synthesis, carbohydrate metabolism, and many other biochemical reactions. It is critical for cell development and so for healthy bone, cartilage and hoof tissue. Zinc deficiency rapidly affects immune function. Similar to cobalt, ruminants have very little capacity to store zinc.

Understanding The Trace Element Status of Your Lambs

Significant deficiencies of essential ‘micro-minerals’ will produce obvious clinical signs such as significant growth defects or recurrent severe infections. However, the effects of deficient diets are often subtle or subclinical; meaning there are no immediately obvious, diagnostic clinical signs which can be attributed to a deficiency of one or more trace elements. Therefore, before blanket administration of ‘multi-mineral’ supplements, it is crucial to find out which elements might be limiting performance in your lambs.

Forage forms the basis for all ruminant diets and knowing the levels of trace elements in your grass or preserved forages is a good place to start. If you do not know which trace elements are already being supplied, or which are in inadequate supply, then it is impossible to make decisions on what should be used as an additional supplement. Further analyses of water, soil and animal tissues (blood) might also be valuable to enable a diagnosis of deficiency to be made.

Further Analysis

Blood or tissue samples are particularly useful where the supply of trace elements in the diet appears to be adequate, yet growth rates, disease levels or other production measures are sub-optimal. For example, lambs may not be able to absorb copper from their diet where there is competition from other elements such as iron or molybdenum. High levels of these copper-hungry competitors mean that copper is inaccessible to the animal, despite being present in adequate levels in the diet. In this case, supplying a form of copper that is ‘rumen-available’ is recommended to combat the effects of the competitors.

Choosing The Right Supplementation For Your Lambs

When choosing a supplement, ‘added extras’ are not always a benefit. Remember that oversupplying any mineral can cause damage to the animal and can even be lethal; particularly in the case of copper. The signs of mineral toxicity can be very similar to those of deficiency so it is always worth working through a process to precisely diagnose the problems. There is a worrying trend in the UK towards trace element over-supplementation which carries a risk not only to the animals but also to the food-chain. Unnecessary supplements result in additional wasted financial costs.

A trace element bolus which releases the required trace elements over a number of months can be a convenient supplementation option. These boluses release trace elements at levels that are compatible with an animal’s daily requirements. They are a particularly good option for the supplementation of trace elements such as cobalt and zinc, which cannot easily be stored by ruminants, making a continuous daily supply necessary to address any deficiency.

It is always worthwhile to consult your vet or nutritionist to help you wade through the data, make an informed conclusion and help choose the correct targeted approach to trace-element management in your flock.

This editorial/ article is supplied by Bimeda UK - manufacturers of the Cosecure Lamb trace element boluses. The Cosecure trace element boluses deliver ionic copper, ionic cobalt, selenium and iodine at a controlled and constant rate, for up to six months.

See bimeda.co.uk or call Bimeda on 01248 725 400, for more information.