Trace Element Supplementation at Grass

Mineral imbalances and deficiencies are quite common in Irish grazing situations, while supplementation at grass can prove difficult, especially where little or no concentrate supplementation is fed.

Mineral imbalances may be noticed in isolation or in combination. Imbalances of major elements may cause rickets, lameness, milk fever, lambing sickness, tetany, reduced appetite, reduced milk yield and depraved appetite. While deficiency of trace elements may cause ill-thrift, abortion/placental retention, perinatal calf death, reduced immunity in calves and cattle. Susceptibility to bacteria and parasites, infertility in cows, reduced fertility in bulls, lowered milk yield, lameness, slow healing of wounds and poor skin/hair quality.

Imbalances and deficiencies present themselves in three main forms; Non-Clinical, Sub-Clinical and Clinical.

Non-Clinical deficiencies are by far the most common, and by their nature the most difficult to detect.  Blood sampling, along with the testing of forage, milk where appropriate and also soil will indicate the issue, and identify which trace element(s) are deficient. Non-clinical deficiencies, if left untreated can become sub-clinical and even clinical deficiencies.

Sub-Clinical deficiencies occur where there are few obvious signs of deficiency, and may in fact manifest as depressions in performance (milk, weight gain, fertility and general health). These can be quite difficult to notice, especially where all animals in the group are deficient, as a large proportion of the group can be displaying similar symptoms.

Clinical deficiencies can display in a variety of ways and are categorised as when over 40% of animals in a group display these characteristics.

As previously mentioned, supplementation at grass can be difficult however there are options:

• Suitable bagged minerals – fed at a fixed rate (or free access where appropriate) are quite effective although somewhat impractical when animals are at grass.
• Compressed block and lick buckets are more practical in a paddock situation, however intakes are not regulated or guaranteed.
• Water soluble trace elements are an effective method of supplementation provided good infrastructure (and no other water source) is in place.
• Drenching is effective but the effects will only last over a short term before re-application is necessary.
• Boluses give a fixed amount of supplementation, at a predictable rate for a given period of time.

Nutribio / CAHL have a solution for your supplementation needs and preferences.

Andrew McInerney, Nutritionist (CAHL/Nutribio)