BUREAU OF ANIMAL INDUSTRY. 113 



prepared and special plans were made up for a number of individual 

 plants. 



EEQUIREMENTS FOR JUI.K PKODUCTION. 



Investigations on the cost and requirements of milk production 

 have progressed to a point Avhere accurate information is now avail- 

 able for representative dairy sections throughout the United States. 

 Two-year studies on groups of dairy farms in Indiana, North Caro- 

 lina, and Vermont had been made previously, and this year the field 

 work for similar investigations was completed in the States of Wash- 

 ington and Louisiana. Investigations are under way in Nebraska 

 and Delaware. The data collected have already been found to be of 

 great value and should help in determining an equitable price to be 

 paid farmers for milk. The reciuirements have been obtained in 

 terms of pounds of feed, hours of labor, etc., so that dairymen may 

 determine the cost of production at any time by substituting current 

 prices for the requirements listed. 



CLEANING MILKING MACHINES. 



In continuation of the efforts to devise a simpler method of clean- 

 ing and sterilizing milking machines so as to prevent excessive num- 

 bers of bacteria in milk, tests were made on farms in Vir.o-inia and 

 Maryland, and while good results were obtained with some methods 

 there is still room for improvement and need for further study. The 

 chlorine-solution method and the hot-water method have been tried 

 out with different makes of machines, and so far the hot-water 

 method for sterilizing all parts has resulted in more uniformly low 

 bacterial counts. The investigations have indicated that many opera- 

 tors do not understand the construction of the machines from the 

 sanitary standpoint and that when they become familiar with the 

 machines and use ordinary care great reductions in the bacterial 

 couirt are obtained. 



OTHER ACTIVITIES. 



Some experiments on the whipping qualities of cream were made. 

 The results indicate that age and fat content, rather than acidity, 

 are the determining factors of the whipping quality, and that cream 

 as low in fat as 20' per cent will whip satisfactorily if held at a low 

 temperature for 48 hours. 



The Dairy Division exhibit at the 1919 National Dairy Show sur- 

 passed all previous efforts of the division. The 10.000 square feet of 

 floor space allotted was taken up with booths representing 12 phases 

 of dairy work. 



Special attention wa5> given by market-milk specialists to the treat- 

 ment of gargety cows, the elimination of garlic flavor in milk, and 

 the effect of silage in causing flavors and odors in milk. Extensive 

 tests on the last-mentioned problem indicate that the flavor and 

 odor oi corn silage in milk is due to cows eating the silage and not 

 to absorption of the silage odor from the air, as commonly believed, 

 and that aeration is an effective means of reducing the flavor and 

 odor. 



Further work on the suitability of the red organism R-2 for test- 

 ing the passage of milk through the retarder in pastouri/ation has 



