310 



MILK 



is necessary, probably more than in hand milking. The vacuum 

 should not be higher than 15 to 15.5, otherwise injury to the cow 

 may result, and the yield is not greater with a higher vacuum. 

 Cows have to become accustomed to the machine, and this is 

 more difficult with some animals than with others. It has been 

 observed that when hand milking is replaced by machine milking 

 there is a temporary shrinkage in yield. This, however, is also 

 true when milkers are changed, and is, therefore, no objection to 

 the use of a machine. The cost of a machine and the cost of 

 installing amounts to nearly $400. It is, therefore, not advan- 

 tageous for herds smaller than 15 cows. 



Fig. 124. Milking machine used in experiments by Lane and Stocking. 

 (Bull. No. 92, B. A. I.) 



The machine must be properly cleaned and the parts kept in 

 brine or an equally efficient antiseptic solution between milkings. 

 Cleaning the machine before use is estimated to occupy ten to 

 twenty minutes, and attention after milking about twenty minutes. 

 This extra time is, of course, more than compensated for by the 

 time saved in milking, as each milker can handle two machines 

 or even three at the same time, and each machine milks two cows 

 simultaneously. In the usual form of machine the milk runs 

 into one pail from two cows. This is a disadvantage when it is 

 desired to learn the productivity of individual animals. Recently 



