SANITARY MILK PRODUCTION 153 



rinse out the cups and rubber connections in cold or tepid water after 

 which they are thoroughly washed in a hot solution of washing powder 

 and rinsed in clean water. Then they are kept in an antiseptic or a 

 germicidal solution, preferably of chloride of lime or bleach. In putting 

 the tubing into the antiseptic, great care must be taken that air pockets 

 do not form and prevent the solution coming into contact with the rubber. 

 When the rubber parts are needed they are carefully rinsed in clean fresh 

 water before using them. The buckets into which the milk flows should be 

 washed after milking and sterilized with steam before being used again. 



An objection that has been raised to the use of milking machines is 

 that if a high vacuum was inadvertently used the cellular content of 

 the milk might be increased or that blood might be drawn from the 

 udder. Breed has found these fears groundless but advises the use of 

 the low vacuum recommended by the makers. 



The point has been made that in machine milking incipient udder 

 trouble is more likely to escape attention than in hand milking because 

 the udder is handled less. This is most likely to happen where two cows 

 are milked into a bucket having a single compartment for slight abnor- 

 mality in the milk is apt to pass unnoticed. Also fear has been expressed 

 that garget might be spread in the herd by the teat cups. In practice 

 this does not seem to have been a serious matter. 



A factor that has operated to impede the introduction of all types 

 of milking machines is that, though they are not too complicated for 

 intelligent dairymen to handle, far more mechanical ingenuity and depend- 

 ability than the average dairy hand has, is required to operate them 

 successfully; so it is necessary to employ a man who commands higher 

 wages. 



Contamination of Milk in Straining. It seems to be the opinion of 

 many dairymen that it matters little whether dirt gets into milk or not, 

 because it can be strained out later. At all events, in many dairies a 

 deal of time is spent straining milk. Of course it is known, since manure 

 and other dirt that gets in milk is partially soluble, that all of it cannot 

 be removed in this way but it is natural to think that the milk will be 

 better for having the visible dirt strained out. Careful experimentation 

 shows that no great amount of improvement is effected in this way. 

 Conn, Stocking and many others have studied the matter and gotten 

 results that are substantially the same. 



Stocking determined the bacterial content of five samples of milk, 

 passed them through three thicknesses of fine cheese cloth, supported 

 on wire gauze and then determined the count of the filtered milk. The 

 results which are those given in Table 42 are such as are obtained when 

 milk is carefully filtered through cheese cloth into clean vessels, and the 

 effect of filtering is therefore shown most favorably. 



