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It’s a well-known fact that there are deficiencies of a number of key trace elements in vast areas of grassland in the UK which has important implications for our livestock.

According to independent grassland expert Dr George Fisher, the best way of diagnosing a deficiency is to focus on your livestock.  At the same time Rumenco’s Technical Manager advocates solving problems through feed supplementation.

Trace Elements in feed not fertiliser


“Although soils may well be deficient in nutrients, the animal could already be well catered for in the diet,” says George, who warns that spending a lot on soil and herbage testing is not the best or most cost effective way of diagnosing trace element deficiencies in livestock.

He suggests that soil tests should not be relied upon alone, but advises farmers to consider a wider perspective before thinking of buying in trace elements.

Trace Elements best address in feed not fertiliser

“If you think you have a problem, work with your vet to blood profile stock and only using grass and silage trace element levels as a back-up for further understanding,” says Dr Fisher.

“For a meaningful mineral profile for your stock, it’s best to take blood samples at times when the deficiency is most likely to show. This should involve 10 percent of the herd, and ideally be taken at a time when the animals are under most physiological stress, such as during early lactation, rapid growth in youngstock and the last trimester (third) of pregnancy,” he adds.

“Although most soils in the grassland west of the UK are deficient in trace elements for animal production, whether or not a deficiency is apparent depends on many factors, including the farming system, levels of milk or meat production and the weather.  But once a deficiency is identified, we then have to decide how best to treat the animal and that means looking at all the options available on-farm.

“There are many solutions available such as boluses, drenches, injections and water treatment, but you’ve got to pick something that is long lasting, cost-effective and covers all your stock.

“Take care with applying trace elements through the soil via a fertiliser.  There are so many complicated interactions going on between soil and plant, and then plant and animal, that this is not the most assured route,” George warns. “When planning your fertiliser regime, focus on the major nutrients of Nitrogen, Phosphate, Potash and Sulphur - getting these absolutely right for optimum grass growth will have the most impact on the quantity and quality.  Then make sure that trace elements are supplied more directly to your livestock.”

Rumenco technical manager David Thornton believes that the best guarantee to get minerals into livestock is by direct feed.

“It has to be the most efficient, simplest and easily controlled way of getting these nutrients into the animal which is crucial for maximising production along with performance,” says Mr Thornton.

“You will find they eat more, when they need it, a form of self-regulation.

“And if you compare it with boluses, for example or drenches, which require one-to-one handling of animals which is not only labour intensive but stressful, time consuming and possibly hazardous too, direct fed minerals has a number of positive benefits.

“Trace elements supplied by licks, or buckets are available 24/7 throughout the grazing season and are tailor made to suit the particular animal and provide a greater degree of control.

“With a number of uncertainties as to whether an animal has ingested the correct amount of nutrients or not, the direct fed mineral application which will be bespoke for the animal’s needs is probably the most certain farmers can be, that they’re supplying their stock and balancing their nutrition.

“Mineral intake is critical as it can have performance limiting effects and wide reaching implications. Grass staggers is an all too common result of a lack of magnesium that can easily be avoided on-farm,” says Mr Thornton, who believes that by predicting where and when the main risks are, farmers can avoid any potential production losses through the direct fed option.