The late Emeritus Professor Tom (T.W.) Walker of Lincoln University wrote in Dolomite, A first class source of magnesium, “it makes good sense to me to correct animal deficiencies through the soil and the plant. If my diet were deficient in protein and carbohydrate, I would rather correct it by daily increments than a great blow out every few months.”

There are few soils in this country where an increase in plant growth can be expected as a result of magnesium being applied.

Magnesium currently applied is for the benefit of animals primarily high producing dairy cows, although the health of any lactating animal is likely to improve markedly with an annual dolomite application.

The number and severity of magnesium related metabolic disorders in spring grows each year due to induced magnesium deficiencies.

Warm wet growing conditions along with the use of synthetic nitrogen and potassium mean magnesium available from soil parent material steadily decreases.

Without replenishment more valuable time is spent treating animals and it is estimated that for every one animal treated for a calcium/magnesium related disorder there are another nine animals where production is lower had the problem not arisen.

Imagine if you will a situation where the number of cows requiring treatment in spring is no more than one in fifty with all those animals regaining their feet without assistance.

There’s more farms every year achieving that status and with the cost of imported magnesium oxide escalating and the availability of uncertain we’re expecting more astute and forward thinking operators to be joining the club.

All it requires is a call to the below listed 0800 number for a price to be obtained and transport to be arranged.

A single application between now and calving provides peace of mind knowing that regardless of weather conditions the health and well-being of valuable animals during calving and early lactation is largely secure.

It gets better than that too.  A single application is sufficient to ensure that the magnesium content of a mixed herbage sample at grazing is between 0.22 and 0.25% throughout the next twelve months.

Animals well fed on pasture with that magnesium content are unlikely to be magnesium deficient any time during the year.

For optimum animal performance Its essential that the rumen is functioning efficiently and over calving when sunshine hours are down extra energy and fibre will be necessary.

Meadow hay is the best option as it is made over summer when sunshine and plant energy levels were at their highest and the fibre is at least 25cm long, the lengthy required for a mat of fibre to form in the rumen.

Balage may also work well provided it was made from pasture with a minimum of 10% seed head, however top-quality meadow hay remains the best.

Hay was dismissed when we were milking cows with the throwaway line, “cows don’t milk on hay”.  That’s fair however when hay is made freely available to animals in spring they eat not a mouthful more than is required to meet their requirements.

On a frosty morning followed by strong sunlight animals will eat little hay, however, will make up for that devouring every last skerrick on a wet morning with a blustery southerly blowing.

The required rate of dolomite to provide peace of mind over spring is 250kg/ha.  That applies close to 29kg of magnesium per hectare with annual maintenance on high performing dairy properties approx. 21kg Mg/ha.

Even if spreading the whole property is not feasible, applying to just the calving areas will still be beneficial and provide a feel for what is possible, with a bin of dolomite available when grazing the untreated areas.

For more information call Peter on 0800 436 566 (4 Dolomite).

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