MINERALS & STOCK

Hawke's Bay Herald-Tribune, Volume 81, Issue 64, 8 December 1937, Page 13

MINERALS & STOCK

Avoiding Deficiency Diseases ! EFFECTS ON HEALTH - 0 Although the live stock industry here and in other countries has reaehed what niight ,be regarded as a reasonable degree of efiicieney without any very great attention being paid to the mineral content of the rations, investigations in recent years have revealed tliat minerals play a particularly important part in the growth and health of the stock. It has long been known that, in addition to its organie contents, the animal body contains a small percentage of inorganic mineraL matter. The most important of these minerals are calcium, sodium, potassium magnesium, iron, phosphorus, sulphur, chlorine and iodine*. These are present only in relatively small quantities, but each has a particular function to perform. Thus, for example, it is a compound of iron whicli carries from the lungs to the tissues the oxygen xequired for consumption in the. body. The waste product of that combustion, the c.arbon dioxide is carried by sodium salts to the lungs for excretion. Similarly _ all other vital activities of the body are regulated directly or indireetly by the mineral elements in the body tissues and fiuids, and the health of the animal is determined largely by the degree of concentration of those elements. For instance, it is known that a deficiency of potassium prevents the heart muscles from relaxing properly, while an excess of that mineral in the animal body may caufce them to relax so coinpletejy that the heart stops beating. Besearch has shown also that not only lnust the concentration of potassium be correct, but there must be also the correct proportion between potassium and other minerajs. It has been demonstratod that any upsetting of these proportions leads to some form of disease and, unless rectified, to death, Cause of Disease. Experirqents in which animals have been ied on rations definitely deficient in one or more minerals, have shown that it can to a large extent adjust the balance, but only at the expense of its health and constitutjon. If tho deficiency be of calcium or phosphorus, the animal draws on its skeleton, which appears to act as a clearing house through which the supply of these minerals to tho tissues is regulated. In cases of deficiency the rigidity of the skeleton may be sacrificed in order to meet the needs of the soft tissues. This explains how conditions of maltnutrition may arise when animals are fed over prolonged periods on food materials that are deficient in mineral. matter, or in which there is an excess of some minerals and a deficiency of others. From time to time outbreaks of disease have been proved to be due definitely to a shortage of one or more of the essential minerals in the pastures or crops which happen to form the main source of the food of the animals coneerned. It has been shown also that these diseases can be remedied by the addition to the ration of the mineral the deficiency of which has been responsible for the outbreak. 1'n addition to these so-called ' 1 deficiency ' ' diseases which are now comparatively well known, there are also, in the breeding, rearing and keeping of stock, frequent losses which ultimately can be traced to the low vigour of the animal. In many cases the feeding may not be at fault, but, on the other hand there can be no doubt that the f ertility of the mother, her capacity for rearing her young and the future health of the progeny, m,ay be vitally affeeted by •conditions of nutrition. With more intensive methods and forced production under artificial conditions the importance of the mineral constitutent of the nation will be more clearly recogni3ed. and it is probable that more systematic endeavours will be made to ensure that the mineral requirements of the animal are adequately met. Pastures Deficient, Already experience has shown that pastures in some districts are definitely deficient in certain mineral elements that may be present in comparative abundance in'the pasture plants of another district. In many cases this diffieulty has been overcome by the top dressing of the pastures or the use of a mineral lick containing, principally, bone-meal or di-calcic phosphato, either of which will supply both calcium and phosphorus. The mineral requirements of young stock, breeding animals and milking cows are greater than is the case with working animals, cattle that are being fattened or dry sheep producing only wool. This applies particularly to calcium and phosphorus, which are the minerals used largely in making bone. It has been established'that the most practicai and economical method of supplying these mineral elements to the stock is by a liberal application of superphosphate fo the pastures on which they are being grazed. Tests with pigs have shown that .at tho stage when the daily increase in weiglit was approximately tho average for the whole period of growth about a quarter of an ounce of lime and slightly more phospliorie acid were assimilated daily, but in order to get these amounts assimilated at Ieast half an ounce of each had to be present in the uaily ration. Tho tests have shown, too, that growth, health and reproductivo capacity th© pigs were all im- •

proved by the addition to the fpod of , salt mixtures containing these and other mineral elements in the proportion in which they occur in sow's milk. Milk Lacks Iron. Milk is uBually lacking in iron, but the young pig is born with a stock of iron in its body — presumably to supply its needs until it is able to find a further supply in its food when it begins to eat at about three weeks old. If during those first three weelcs the young pig grows so rapidly that it exhausts its stock of iron, anemia, with its .attendant evils, may ensure, and frequently death will take place during the dilation of .tho heart before the other symptoms become apparent. If, on -the other hand, the sow is carefully fed, so that her milk is good, and the pigs are allowed to run about on pasture and supplejnent the milk diet aecording to their instincts, they go forward without a check. Numerous other effects of mineral deficiency could be quoted, but sufficient has been said to indicate the important part these elements play in the health of stock. Fortunately, the problem of ensuring that there shall be no deficiency of minerals in the ration is not a difiieult one. It is a very simple matter to provide a mineral lick ior the stock. These are not expensive, and provided they are offered to tho stock in suitable containers there should be little waste. On propertios where the pastures are top dressed regularly a suitable lick can be made up of 80 parts of common salt to 20 parts of bonemeal; but where top dressing is not practised the -propor tions should be reversed — that is, 20 parts of common salt to 80 parts of bonemeal. A compound salt lick xecommended by the Victorian Department of Agriculture to meet any likely mineral deficiency may be made up as follows: — Salt, 71 lb.; dicalcic phosphate, 15 lb.; sulphur, 5 lb.; mola'ssos, 5 lb.; magnesium sulphate, 3 lb.; sulphate of iron, 1 lb.; potassium iodide, 1 oz., and manganese sulphate, 1 oz.