The last dolomite article contained the quote by the late Tom Walker, a past Emeritus Professor of Soil Science at Lincoln University, “It makes good sense to me to correct animal deficiencies through the soil and the plant.”

When animal deficiencies are corrected in this way, not only is animal performance enhanced, soil health and subsequent pasture performance also improves.

There is now a growing awareness of the inexorable link between soil, plant, and animal health.  Persistent animal health issues in spring are a symptom of less than ideal soil health, and supplementing cows with magnesium via water troughs or dusting is little more than a temporary quick fix.

By addressing the real issue, the availability of magnesium for plant uptake, plant and animal performance lifts, costs come down, and the frustration of not knowing when the next animal will require attention rapidly diminishes.

In our experience the only fail-safe way of doing this is by an annual application of Golden Bay dolomite.  It may be applied at any time during the year. However, with the greatest demand time for magnesium being prior to calving, autumn is the ideal time to apply.

Animal systems are unable to efficiently store magnesium, so it is essential that sufficient is eaten  each day to meet their demand.  The obvious and most effective way of doing this is to ensure that every mouthful of pasture contains a healthy amount of magnesium.

Last autumn a property, with a history of numerous severe and persistent calcium/magnesium related metabolic disorders in spring, applied a fertiliser mix containing 217kg/ha of dolomite, which applied 25kg/ha of magnesium.

Calving in spring was largely trouble free, with only a handful of animals requiring treatment, and all responding rapidly. A marked and welcome change for a farmer in a district where severe metabolic problems are regarded as normal.

This is only one of many instances reported over the twenty eight years of supplying dolomite to intensive high performing dairy properties, and the reasons for the outstanding performance are now well documented and understood.

Trial work conducted at Massey University on magnesium fertilisers highlighted the superior performance of dolomite in lifting Soil Exchangeable Magnesium, when compared with other magnesium products currently available.

Dolomite is naturally occurring carbonate rock, different from limestone in that it contains 11.5% magnesium, and 24% calcium, compared to around 35% calcium and no magnesium in high quality agricultural lime.

Fineness of grinding of dolomite is a key to the almost immediate lift in the magnesium content of pastures, and the subsequent improvement in animal demeanour and overall health.  Animals with sufficient magnesium in their diet become content and increasingly docile, making yarding and handling an easier and more pleasurable activity.

Magnesium also aids the uptake of phosphorus by plants. An important factor to bear in mind when deciding on nutrient inputs this autumn.

Having a pH modifying, or ‘liming’, effect greater than limestone, means that where soil calcium and pH levels are already generally adequate, dolomite is an ideal maintenance product.

The outstanding improvement in general animal health and performance may not be solely attributed to the magnesium and calcium content of dolomite.  The Golden Bay deposit was initially a seabed deposit and, as a result, also contains a wide range of essential trace elements and minerals.

As soils weather over time, mineral content of the topsoil is steadily lost.  Although only present in very small amounts, the boron, cobalt, copper, manganese, molybdenum, and zinc contained in dolomite will  be beneficial, particularly on soils where those elements are deficient.

There are very few pastoral situations where more than 220kg/ha (25kgMg/ha) of dolomite is required to obtain the animal health and performance benefits discussed.  At this rate a truck and trailer load of 28 tonnes is sufficient for 127ha.

Dolomite is available nation-wide and, if not in stock at your local fertiliser supplier, it can be delivered within a few days.  It may be mixed with any non-nitrogen fertiliser product or applied separately at any time, as the only effect on animals eating it is beneficial.

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