The pre-calving management period is a key time to set up the herd for calving, lactation and return to service and is vital for healthy calves. One aspect which must be considered is trace element status. We’re generally very good at realising the importance of nutrition in terms of energy requirements but we shouldn’t neglect the importance of adequate mineral status.
The trace elements with the most significance during this period are copper, iodine and selenium -partially because of their importance for healthy offspring and partially because of their role in fertility.
Iodine is integral to the thyroid hormones which increase the rate of absorption of carbohydrate from the gastrointestinal tract and control metabolism. This trace element should be a key consideration pre calving as deficiency can result in still born or weak calves which are slow to suckle.
Selenium plays a role in the immune system, fertility, muscle tissue health and iodine utilisation. Animals deficient in selenium can give birth to calves affected by white muscle disease which occurs when the muscle tissue becomes damaged and unable to function. Deficiency of selenium is also a risk factor for retained foetal membranes which can increase the time taken to get back into calf.
Copper is the trace element which gets the most attention in terms of reproduction. Copper is an essential component of a number of different enzymes which allows the animal to thrive including enzymes responsible for energy utilisation and fertility.
How Can I Tell if my Stock are Deficient?
There are a number of diagnostics available for determining the trace element status of animals. The simplest way to get a good picture is to use forage analysis in conjunction with blood samples. Imbalances should be investigated allowing plenty of time to implement any potential nutritional changes which may be required. As a result I recommend trace element blood sampling 3 months prior to calving to ensure the optimum response if supplementation is required.
Soil mineral analysis: It should be remembered that whatever is grown in that soil will selectively uptake trace elements to meet its own needs therefore it will not directly correlate with the forage which the animal will eventually consume. As such it is useful additional information if available but I would never recommend it for determining what action, if any, if required.
Water Testing: It should be remembered that water may contain antagonists which can interact with other trace elements. As a general rule mains water is not a concern but if you use a borehole supply, there is potential it could be high in antagonistic trace elements (such as iron or sulphur) which may interact with copper.
Forage mineral analysis: This is a key tool in determining the animal’s trace element status. It tells us how much trace element is available to the animal but it does not give us information about any interactions occurring between trace elements in the animal. You must also take into account any other form of supplementation which is being provided such as concentrates, bolus etc.
Trace element blood sampling: This is vital to investigate a trace element deficiency. While it may be seen as an expensive endevour to perform blood sampling, the cost of poor productivity (which can result from deficiencies or toxicities) is far more. The parameters measured will depend on what your vet determines is necessary based on history and clinical presentation of the animals. However, I would generally recommend looking at copper, iodine and selenium as a minimum in cattle.
Liver Copper: The liver is the organ which stores copper in ruminants and can give us an idea about the longer term copper status of the animal. It’s possible for vets to perform liver biopsies in live animals and you can request samples from the abattoir for monitoring.
Which Form Of Trace Element Supplementation Is Best?
There is an array of different forms of trace element supplementation available and it can be difficult to know which is best for your herd. Let’s take a look at the advantages and disadvantages of some of the most popular methods:
Drenches can be a cheap and convenient option however they are relatively short acting and repeated doses mean greater labour. For trace elements which cannot be stored in the body, such as cobalt or iodine, they are not appropriate to treat deficiencies, as a form of continuous supplementation must be supplied.
Free Access Systems, Such as Licks and Blocks
Where a need to supplement trace elements has been established, we need to ensure that all animals receive an amount of trace elements which is compatible with their daily requirements. Too much of a trace element can prove toxic; too little and the deficiency will not be addressed. Unfortunately, the free access lick and block systems do not provide this guarantee and an independent study highlighted that intakes between animals are extremely variable, with some consuming nothing and others consuming excessive quantities. 1 A more scientific approach to supplementation is required.
Injections can be suitable for targeted administration in conjunction with the advice of your vet. They can be appropriate where only a single trace element, such as copper or selenium is required.
In Feed Supplementation
Trace elements can be provided by the provision of TMR, concentrates or bag minerals.
Often these are specified based on ‘averages’ or ‘common requirements’ as opposed to being based on what has been determined is deficient and required on farm. Ideally these mixes should be prepared based on an investigation in to the animals’ trace element status and requirements. This method can add significantly to the cost of production and can be difficult for extensively managed cattle.
Trace Element Boluses
Boluses provide an convenient, cost-effective and controlled method of trace element supplementation. Bimeda soluble glass bolus CoseIcure cattles provides exactly the same amount of copper, cobalt, selenium and iodine every single day for up to 6 months in cattle.. This means there are no variable intakes and no variation between animals. The continuous, controlled release of the bolus is particularly important for animals requiring cobalt and iodine which cannot be stored in the body and therefore a daily supply is required. Their long-lasting nature is also highly convenient and reduces labour costs as regular bolusing is not required.
- Blood testing in conjunction with forage analysis in the simplest way to obtain information on the animals trace element status
- Deficiency of trace elements can cause poor productivity but there are many other causes which your vet may advise you also investigate
- Over supplementation does not improve productivity and can be dangerous, particularly where selenium and copper are concerned.
- Establish the need before supplementing with trace elements
CoseIcure cattle bolus contains copper, cobalt, selenium and iodine and lasts up to 6 months in cattle.
Before supplementing trace elements, particularly copper and selenium which can be toxic, it is recommended that you seek advice from a vet or nutritionist.
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.
1. McDowell, 1992