Minerals Are Important In Diet Of Stock

Dominion, Volume 32, Issue 65, 9 December 1938, Page 35 (Supplement)

Minerals Are Important In Diet Of Stock

Judicious Use Of Fertiliser For Topdressing

THROUGHOUT the world increasing attention is being paid to the part played by minerals in the maintenance of health in livestock; we no longer accept the law of the survival of the fittest as being applicable to modern requirements. The concentration of livestock in comparatively small areas with a high carrying capacity has brought out weaknesses that call for attention if carrying capacity and production are to be maintained. Literature published from time to time by research institutions describes some outstanding examples of malnutrition among livestock running under natural conditions on large areas of country. In South Africa a form of malnutrition, the outward signs of which are wasting away and ravenous appetite for old bones and decaying carcases, has been definitely identified as phosphate starvation. In the Falkland Islands a great deal of trouble in the rearing of livestock has been experienced. A report on this problem, following ;! close investigation on the spot, stated that rearing of lambs was difficult, and deaths taking place up to weaning

time left less than 50 per cent, of the lambs dropped. It is also on record that thoroughbred horses imported into these islands have, in the course of two or three generations, gone right back to pony size—-the reason given being that the naturally low mineral content of the native pastures is not capable of sustaining other than undersized stock. In many other countries malnutrition problems have risen, and always it has happened that a shortage of one or more essential mineral is the underlying cause. Here in New Zealand we have our own peculiar problems, of which perhaps most widely known are the bush-sickness of the pumice lands, and the iodinedeficient areas in the lakes district of Central Otago. In the case of the bush-sickness areas, it is considered that deficiency of cobalt in soil and pasture is responsible for most trouble with stock. In Central Otago, where troubles have been experienced. lambs have been born with, or have quickly developed. enlarged glands and joints. 'J his condition is traceable to shortage of iodine in the food, and consequently in the system. We have, however, right throughout New Zealand a form of malnutrition that represents serious loss, both national and individual, but which, unfortunately, has been given very little concentrated attention, the reference being to malnutrition that has as outward signs sterility, abortion and milk fever, and which, in some districts, affects 30 per cent, of the dairy cattle

population. It would be difficult to make even a rough estimate of what this particular form of malnutrition costs the Dominion every year, but the sum must be enormous.

It is comparatively easy to trace the development of this state of affairs from the earliest days of settlement up to the present day. Where the stock-carry-ing capacity of the country was low and grazing areas extensive, troubles were few; indeed, nature's own law of "survival of the fittest’’ was accepted as inevitable. As the land became more closely settled, grazing areas grew more confined, and every effort was made to increase carrying capacity,. With every advance in these directions settlers were increasing risks associated with keeping livestock, merely by hastening the day when the natural resources of the soil became insufficient to meet completely the requirements of the stock. This state of affairs was most pronounced in more or less specialized dairying districts, where concentration of stock was. and still is, greatest.

Evil Remedied To meet the position of heavy stocking and the race . for increased production, recourse was made to artificial fertilizers. The me of such fertilizers, specially 'iipi'rphosphate., had a marvellous effect in consolidat- ; lug what had been gained, and in even still further increasing carrying capacity. Further progress fol- ' lowed the study of pasture mixtures, and the laying down of better quality, more permanent grasses. In- ■ vestigations into pasture management problems resulted ’ in increased production and better utilization of feed, I Now, having reached what appears to be a maximum ; carrying capacity, farmers are faced with troubles that ; reduce the productive capacity of herds and con- : seqiiently the income from the farm. , /Among the : causes responsible for that 30 per cent, herd wastage i are temporary sterility, slips, milk fever, mammitis, ' ilue, at least in part, to some form of malnutrition. By' ; being deprived of some essential mineral element in ; their food, cattle have, a lowered resistance to diseases,, bacterial and otherwise, that should pass them by. The outstanding need in our agricultural world todav is an adequate supply of minerals to livestock,specially heavy-producing cows; it is only by paying attention to this question that we can hope to reduce the appalling wastage that now takes place in many of; the herds in the Dominion. It is not sufficient to have; plenty of grass unless that grass contains the essen* > rial minerals in adequate supply and in the correct bal- . ance to meet all requirements of stock. Great Reserves

fortunately, the world at large contains extensive reserves of all minerals at present known to be essential. The cost of these minerals is not beyond the purchasing capacity of the man on the land. Realizing that the correct and natural means of getting minerals to stock is through their food, we have developed the practice of topdressing pastures and fertilizing fodder crops in such a way that pastures and crops may take up what they require. The mineral content of the soil is reflected in the mineral content of the crops and pastures, and this in turn is reflected in the condition of the stock grazing there. Deficiencies of lime, phosphoric acid, potash, calcium, are passed on from the soil to the stock.

Direct evidence of the effect on pastures of fertilizers supplied to the soil is contained in a report published recently in the journal of the American Society of .Agronomy. This report states that "the phosphoric acid content of pasture grass was increased by means of superphosphate to a particularly noticeable extent — actually, on an average, by 60 per cent. If, in addition to superphosphate, lime or potash were applied a further moderate increase in the phosphoric acid content of pasture grass was noticeable/’ That being so, it becomes of utmost importance that fanners should exercise care and selection in ihe purchase of topdressing manures. It may not be sufficient to topdress with phosphates alone: it certainly is not sufficient if the soil concerned happens to be deficient in lime and potash. Correct manuring, specially for autumn and early winter, under dairying conditions, would be first a dressing of finely-ground limestone at the rate of from 5 to lOcwt. per acre, to be followed later by a dressing of from 2| to 3cwt. of super and | to lewt. of 30 per cent, potash salts per acre. The minerals represented by such treatment are: Phosphate, calcium, sulphur, potassium, chlorine, sodium, all of which are essential to the well-being of stock. The use of lime and correct manures-constitutes the only sound method .whereby a heavy concentration of stock can be sustained in a perfectly healthy condition