THE CLASSIFICATION OF MARKET MILK. By A. D. MELVIN, Chief of Bureau of Animal Industry, United States Department of Agriculture. In providing for the classification of milk, the primary object is to exclude all milk which may be harmful to the consumer and to provide for milk that will be wholesome and nutritious. In doing so the restrictions should not be more burdensome than necessary to accomplish this result and should not eliminate milk as an article of diet for the poor. The danger of using raw milk from diseased cows, improperly constructed dairies, improperly handled, and various other causes, has been clearly shown, and it is therefore imperative that no raw milk be sold, except when those in authority know that it is safe to be used in that condition. Raw milk of the highest standard should be produced for the use of infants and invalids and for those who desire to use only such milk and who are willing to pay for the greater cost of production. A wholesome supply of raw milk which can be furnished without involving unreasonable cost should be provided for others. A third class includes undoubtedly the largest proportion of milk which is at present time furnished for consumption and is unsafe for consumption in the raw state. To immediately remove from consumption this supply would result in such an increase in the value of all milk as to place milk as an article of diet beyond the reach of the poor. It seems necessary therefore to provide some means of rendering safe all milk of doubtful quality, and this can only be done by pasteurization under supervision. The work of testing with tuberculin all cows supplying milk to a city of considerable size is an immense undertaking and must necessarily consume much time. Much time is required also in providing suitable cow stables, milk houses, and a pure water supply in all instances where such essential features are lacking. It is probable that from 15 to 25 per cent of dairy cows when tested with tuberculin will be found to react. These cows should be replaced by healthy ones. Facilities must also be provided for delivering milk at a reasonable temperature. It has been demonstrated that cows showing no physical evidences of tuberculosis may be affected with tuberculosis and secrete milk containing germs of that disease; also that the feces of such cattle are contaminated with that bacillus and particles of such feces can readily gain entrance into milk. It seems necessary, therefore, that pasteurization must be included for some time, or until all doubt as to the healthfulness of the milk is removed, in any classification of milk for city use. It is therefore recommended that the classification as recommended by the members of the conference appointed by the Commissioners of the District of Columbia to report upon the milk supply for the city of Washington be adopted as follows: CLASS 1. CERTIFIED MILK. The use of this term should be limited to milk produced at dairies subjected to periodic inspection and the products of which are subjected to frequent analyses. The cows producing such milk must be properly fed and watered, free from tuberculosis, as shown by the tuberculin test and physical examination by a qualified veterinary surgeon, and from all other communicable diseases, and from all diseases and conditions whatsoever likely to deteriorate the milk. They are to be housed in clean stables, properly ventilated, and to be kept clean. All those who come in contact with the milk must exercise scrupulous cleanliness, and such persons must not harbor the germs of typhoid fever, tuberculosis, diphtheria, and other infections liable to be conveyed by the milk. Milk must be drawn under all precautions necessary to avoid infection, and be immediately strained and cooled, packed in sterilized bottles, and kept at a temperature not exceeding 50° F. until delivered to the consumer. Pure water, as determined by chemical and bacteriological examination, is to be provided for use throughout the dairy farm and dairy. Certified milk should not contain more than 10,000 bacteria per cubic centimeter, and should not be more than 12 hours old when delivered. Such milk shall be certified by the health officer of the District of Columbia. CLASS 2. INSPECTED MILK. This term should be limited to clean raw milk from healthy cows, as determined by the tuberculin test and physical examination by a qualified veterinary surgeon. The cows are to be fed, watered, housed, and milked under good conditions, but not necessarily equal to the conditions provided for class 1. All those who come in contact with the milk must exercise scrupulous cleanliness, and such persons must not harbor the germs of typhoid fever, tuberculosis, diphtheria, and other infections liable to be conveyed by the milk. This milk is to be delivered in sterilized containers, and is to be kept at a temperature not exceeding 50° F. until it reaches the consumer. It shall contain not more than 100,000 bacteria per cubic centimeter. CLASS 3. PASTEURIZED MILK. Milk from the dairies not able to comply with the requirements specified for the production of milk of classes 1 and 2 is to be pasteurized before being sold, and must be sold under the designation "pasteurized milk." Milk for pasteurization shall be kept at all times at a temperature not exceeding 60° F. while in transit from the dairy. farm to the pasteurization plant, and milk after pasteurization shall be placed in sterilized containers and delivered to the consumer at a temperature not exceeding 50° F. All milk of an unknown origin shall be placed in class 3 and subjected to clarification and pasteurization. No cow in any way unfit for the production of milk for use by man, as determined upon physical examination by an authorized veterinarian, and no cow suffering from a communicable disease, except as specified below, shall be permitted to remain on any dairy farm on which milk of class 3 is produced, except that cows which upon physical examination do not show physical signs of tuberculosis may be included in dairy herds supplying milk of this class, although they may have reacted to the tuberculin test. This milk is to be clarified and pasteurized at central pasteurization plants, which shall be under the personal supervision of an officer or officers of the health department. These pasteurizing plants may be provided either by private enterprise or by the District Government, and shall be located within the city of Washington. By the term "pasteurization," as used herein, is meant the heating of milk to a temperature of 150° F. or 65° C. for twenty minutes, or 160° F. or 70° C. for ten minutes, as soon as practicable after milking, in inclosed vessels, preferably the final containers, and after such heating immediate cooling to a temperature not exceeding 50° F. or 10° C. No milk shall be regarded as pure and wholesome which, after standing for two hours or less, reveals a visible sediment at the bottom. of the bottle. No dairy farm shall be permitted to supply milk of a higher class than the class for which its permit has been issued, and each dairy farm supplying milk of a specified class shall be separate and distinct from any dairy farm of a different class; the same owner, however, may supply different classes of milk, providing the dairy farms are separate and distinct, as above indicated. |