FARM NOTES.

Hauraki Plains Gazette, Volume XXXV, Issue 4746, 3 September 1924, Page 4

FARM NOTES.

HEALTH OF STOCK. MINERAL REQUIREMENTS. The ultimate purpose of crops grown on the farm is largely the feeding of stock. The sucessful grower of the former, eays Mr Arthur Crichton, writing in the Scottish Journal of Agriculture, depends to a great extent on the presence in the soil of an abundant supply of these minerals considered to be essential to growth. The well-known general principles of manuring are based on an estimation of the amounts of these essential manures removed by the crop. To maintain fertility there must be a return to the soil of amounts of soil nutrients equal to these taken off in the crop. These considerations, which are recognised in arable farming, are equally applicable to the raising of stock. While turnips, for instance, which is the crop to which the largest quantities of mineral manures are supplied .contain approximately six pet cent, mineral matter, the. body of a mature steer may contain as much as four to five per cent. Therefore, if the necessity for mineral matter can be gauged by the amount required, an adequate supply is as essentia! in the feeding of stock as in the growing of crops ; indeed, a deficiency of phosphates or of lime in the ration of a young, fast-growing anima! may be attended with just as drastic results as in the case of a crop where such deficiency leads to slow growth, bn unhealthy plant, poor bulk, and a greater susceptibility to disease.

Most important is the question of the dairy cow and its mineral requirements. It Is one of the most important in nutrition and experiments in connection with this problem are being conducted at the Rowett Institute. As far as the mineral part is concerned there fe usually a deficiency of some of the minerals and an excess of others. The greater the disparity between the supply in the food and the demand for milk the greater is the drain upon the bones and tissues of the cow to keep up the supply. The result is that a heavily-milked cow is often ready to go on to the grass in the spring time with a skeleton depleted in mineral matter, a weakened constitution, a lowered resistance to disease. It is while she is in this weakened condition, before she is enabled to replenish her diminished store from the fresh young grass, that she is most susceptible to disease. It is possible that feeding has much more to do with the incidence of such infectious diseases as tuberculosis and abortion than is commonly supposed.

Before a cow can produce a large amount of milk and still remain free from disease she must be bred from a high-milking strain, fed when young so as to develop a ptrong constitution to enable her to resist disease, be a regular breeder of strong, healthy calves and fed when milking and in calf so that her constitution is impaired to as small a degree as possible. The part played by the, mineral elements in the feeding, of the dairy cow is one which has received remarkably little attention, but from observations already made it would appear as though they played a vital part ir. the production of the healthy, economic cow.

To balance a ration carefully, as far as the mineral matter is concerned, dees not simply mean the addition of an adequate supply of all the minerals considered to be deficient, for excess may be just as harmful as deficiency. Therefore salt mixtures which are said to contain all the essential minerals will not be beneficial in all caseis, for they may sometimes be supplying additional salts already' in excess, and thus dp positive harm. Each individual ration requires to be balanced in itself, according to the requirements of the particular kind of animal, and we are yet very far from knowing the requirements for the different minerals, for these depend to some extent on the amounts and kinds of all other minerals present, and also on the amounts and kinds prepent of the essential constituents other than minerals, When further research work, ip done it may quite well be found that we shall have to altei; our view considerably as to the meaning of a balanced ration, for “albuminoid ratio” and “feeding standards” were worked out without reference to the mineral content of the ration, and it is possible that a propei adjustment of the mineral ratio at the various stages of growth may lead to a more economical, use of protein and a lower consumption of food to produce a given amount of live weight.

It is remarkable how little attention, has been paid to thie aspect of nutrition. At the present day, though it is known that mineral deficiencies do exist and have a profound effect on the rate of growth and on the health of stock, we do not know what amounts or proportions of all the different essential minerals are necessary for each class of animal. There is urgent need for much scientific research work, accompanied' by feeding experiments on a practical scale, to obtain information of practical v alue. Until this work is completed it is premature to offer practical advice to stock-feeders with regard to the addition of mineral mixtures to feeding stuffs.