SANITARY INSPECTION AND ITS BEARING ON CLEAN MILK. By ED. H. WEBSTER, Chief of Dairy Division, Bureau of Animal Industry, Department of Agriculture. In discussing this subject it will be assumed that the herd is in perfect condition as regards health, that there are no persons employed in or about the dairy suffering from any communicable disease, and that the water supply has been examined and found pure. This assumption is made with the understanding that if any of these conditions are not complied with the milk will be debarred from the market, or under certain prescribed regulations be allowed sale after pasteurization. CLEAN MILK. It is evident that in nature's scheme for the nourishment of the young milk was never intended to see the light of day, and if suckled from a normal, healthy gland is the perfect food for the offspring. In this natural method of nourishment there is little possibility of contamination from outside sources. As soon as the artificial method of drawing milk is resorted to there enters a whole set of conditions entirely new and different. The milk then comes in contact with the air, the vessel into which it is drawn, and with particles of dirt from many sources. The problem of securing clean milk-i. e., milk as near as possible to the condition as it exists in the udder-is the problem of dairy sanitation. To put it in another way, it is the problem of reducing contamination from all outside sources to the least possible factor. WHAT IS CONTAMINATION. If the mere presence of solid particles of dirt so frequently found in the milk were the only damage wrought, the question would resolve itself into the simple operation of straining or passing the milk through a clarifier. The presence of solid dirt is, however, an indication of much more serious conditions. Bacteriology teaches that every particle of dirt, whether it seems to the eye a source of contamination or not, carries with it great numbers of bacteria, and that milk at ordinary temperatures, 65° F. to 100° F., is an excellent. medium for their growth, and most of the changes that take place in milk can be traced directly to such action. Neither straining nor clarifying will remove the bacteria from the milk, hence the necessity of keeping the dirt out, not straining it out. SOURCES OF CONTAMINATION. From the act of milking to the final consumption of the milk the possibilities of contamination are many and varied in character. Everything that comes in direct contact with the milk may be a source of trouble, and many things may act indirectly and seriously affect the results desired. MILKING. The first contamination usually begins with the act of milking. If the udder and flanks of the cow are covered with the dirt of the yard or stable the process of milking will dislodge a greater or less portion of this filth, causing it to fall into the pail. The amount of filth that may be on a cow will depend very much on the condition of the stable yard, and floor, gutter, and bedding in the stables. The following illustrations are used to better show conditions which are too common the country over. The condition of the cow shown in Fig. 1 is not exaggerated. The milker is probably all unconscious that he is sowing the seeds of contamination and destruction, which may sooner or later cause the death of infants who are unfortunate enough to be fed from milk produced under such circumstances. 'If he is aware of this fact he is criminal in purpose and intent, and the most stringent penalties should be provided to stop such work. Figs. 3, 4, 5, and 6 show exteriors and interiors of barns which will contribute to such a fearful condition. As to the amount of filth that will get into the milk and the result on the product, reports from the Illinois Experiment Station and Storrs (Conn.) Experiment Station are here quoted: The average weight of dirt which falls from muddy udders during milking is 90 times as great as that which falls from the same udders after washing, and when udders are slightly soiled it is 32 times as great. (Bulletin No. 84, Illinois Experiment Station.) Wiping the flank and udder of the cow with a damp cloth just before milking is a very efficient method for reducing the number of bacteria which falls into the milk pail. (Stocking.-Bulletin No. 42, Storrs Experiment Station.) An average of 13 experiments at Storrs station showed the following results: Bacteria in milk from unwiped udders per c. c.. Decrease due to wiping.... 7,058 716 6,342 14. DIRTY FLANKS. A COMMON CONDITION IN WINTER. FLANKS BECOME CAKED WITH MANURE, WHICH THERE IS OFTEN NO THOUGHT OF REMOVING. THIS IS THE SOURCE OF MOST OF THE DIRT FOUND IN MILK IN WINTER TIME. |