THE MILK SUPPLY

Dominion, Volume 14, Issue 277, 17 August 1921, Page 8

THE MILK SUPPLY

ENSURING WHOLESOMENESS (By Dr. J. A. Gilrutli, in the Melbourne “Argus.”) That the discussion of the necessity and the possibility of securing a pure milk supply, for infants particularly, is being continued throughout the winter months, is a hopeful sign that something definite may eventually be accomplished. Such discussions have been in the past, almost confined to summer, and with the advent of cool months interest flagged. Hence., probably, the continuance of unsatisfactory conditions. When a pure milk supply becomes the subject of public attention it seems that certain facts, now well enough known, are not always borne in mind. These facts arc: 1. Milk within the udder ot a healthy cow is pdactically sterile.- Tho contents of the terminal canal in Urn teat generally contain organisms which have entered through the orifice; but, if the first, few teaspoonfuls bo discarded, the remainder of the milk, as it leaves the udder, is generally germ free. This has been proved time and again. 2. The causes of the deterioration of milk, therefore, are introduced from without, during or subsequent to the process of milking. 3; Disease, especially of the udder, is not necessarily very obvious, and can often only be detected by trained inspectors, sometimes aided by special appliances. This is notably tho case with tuberculosis, and with it purulent form of maimnitis, or inflammation of the udder, neither of which may perceptibly inconvenience the animal. We have, therefore, in an ordinary milk supply to deal with external contamination dnd internal contamination. Different principles are necessary for the prevention of each. External communication probably occurs to the greatest extent during the process of milking. The entrance of the cows into the milk-ing-shed stirs up a certain amount of dust, often impalpable. When the cows are bailed the fine particles gradually settle, and so a number get into the pails. As this dust is to a great extent dried dung, containing myriads of microbes. it is a fruitful means of contamination. Then the milker, pressing the head against the flank, dislodges dust and dirt from the skin, and the movement of the hands in milking adds more particles of dirt from the skin of the udder and from the- clothes, if fresh overalls are not used daily. It has been demonstrated by Professor Dolepine and others that specially constructed milkcans, almost completely covered, leaving but a small hooded inlet, especially if a sterilised strainer be fitted, reduces the danger of this contamination very greatly. Properly constructed milking sheds,' and scrupulous cleanliness, thorough cleanliness of the milker, and washing the udder, all reduce contamination. Other potent means of contamination are tho milk-pail, tho milk-cans, and, indeed, ull vessels which contain the milk from the time it leaves the udder till it is consumed. Milk forms an excellent medium for the growth of many bacteria. That is common knowledge to-day. But milk may contain as many as 100,000, and even mor;-, bacteria per drop, and yet be apparently sound. When a milkcan is emptied on its round the small quantity that is left is apt, in hot weather, to become partially or wholly dried on the ..sides, and particularly tho corners of the can. This is not removed by ordinary washing, and meanwhile the bacteria multiply rapidly. They are protected by the dried milk, and are not killed by ordinary scalding. The vessel, indeed, has become more difficult to sterilise by far. Prolonged steaming is necessary. How often is this done? Very few dairymen have the necessary apparatus. ' The same criticism can be made of the householders’ attention to milk vessels. Ordinary washing is not. nearly sufficient. Scalding with boiling water even is seldom effective if any milk has been allowed to dry. The consequence is that were the milkman to deliver sterile milk into many of the consumers’ jugs and cans serious contamination would immediately occur. It is obvious that no system of inspection can ever eliminate, all these dangers. Only a thorough knowledge on the part of everyone who has Ihe handling of milk, from the cow to the drinker, can effectively diminish them. Of course, frequent inspection of dairy premises, stock, and utensils by trained inspectors, especially men anxious to educate, rather than punish, does much. The general appearance of the premises is an important guide ns to the care exercised by the owner. Refrigeration prevents tho growth of microbes; it does not eliminate the dirt. II: does not kill the bactery ; it delays their multiplication only */ll the temperature rises to a suitable degree. Aliov** -ill. it in no way less/is the danger from the tubercle or consumption germ, if present in tho milk, .or even of the mammitis germ, which has been found associated with ep domies of -sore throat. x As to disease, particularly tuberculosis in cows, it. is encouraging to note that a survey of the milk supply by proper laboratory tests is to be made. But it is well to remember that: a tubercular cow, even when the udder is affected with tho disease, does not continually pass tho bacilli with tho milk. Hence, while a positive result is valuable', a negative test does not mean freedom. The uddor may be perfectly healthy, and tho milk tlicroin free of tho germs, but they may be introduced by means of particles of dry, contaminated dung. It is held by some that this is one of the most frequent means by which, calves contract tho disease from their mothers, the surface of the udder and teat becoming contaminated first. It is recognised in Europe and Amqrica that much of tho tuberculosis in children is due to the bacillus of the bovine type, the assumption lieing that it has been contracted through contaminated cow’s* milk. In Australia, little or no work has been done to determine the extent of the bovine type of human infection. Tuberculosis of cattle is common in Australia, though not to the extent recorded ini Europe and America. There are, therefore,' fewer difficulties in its eradication. That, tuberculosis may be entirely eliminated from herds has Been demonstrated over and over again. Ten years ago the United States Federal Government, which controls the district of Columbia, in which the capital, Washington, is situated, decided to make tho attempt to eradicate the disease from the herds of that territory. Compulsory testing with tuberculin was introduced, and tuberculosis has virtually disappeared, though originally 19 per cent, of tho animals were affected. It is maintained that the expense would lie prohibitive were such a course made general. Yet I could not satisfy myself that milk was dearer in Washington than in other American cities. But did it add a penny per quart to tho price, then it should not be grudged. Milk would still lie much cheaper than beer. And it is a. vital necessity—imperative for children. Indeed, Professor M’Collum, of Baltimore, deems its consumption by everyone so wise a course, particularly in view of its richness in the mysterious vitamiues, that ho states no household should purchase meat until each member can be supplied with, a pint of milk a d a -. Such an important element of our food supply—an element so liable to deterioration’ so liable to become a vehicle for disoase-.-eannot be too seriously treated and no effort ought to be spared by authorities, general and local, and by individuals, to maintain that supply at the verv hig’hcst standard of purity possible.' It is to be hoped that public interest will be continued till tms is effected.