DAIRY FARMING 42I 



at zero to five degrees above by mechanical refrigeration so that ice is not used until 

 the ice cream is packed in tubs for delivery. 



The hand driven quart ice and salt freezer has been superseded by batteries of a 

 score or more of 10 gallon, often individually electric driven, brine freezers. It was 

 estimated that 138,000,000 gallons of ice cream were made in the United States in 1911- 

 12, representing over 150 millions of dollars paid by the consumers. 



Market Milk. In cities of any size the milk man who delivers the milk produced 

 by his own cows within driving distance of town has been displaced by the distributor, 

 who buys milk by the car or even train load from the country as many as 400 miles 

 distant, and employs wagons in many cases to the number of 500 and over to distribute 

 it to the consumer. An increasingly large proportion of this milk is pasteurized before 

 distribution to guard against dissemination of disease and to prolong keeping quality. 

 Recent investigation has convinced the thoughtful student of the problem that flash 

 pasteurization, heating to 165 degrees momentarily and immediate cooling, ordinarily 

 fails to remove the danger of disease due to bacteria. This method is rapidly being 

 superseded by the " holding system," i.e. heating to a temperature of 145 to 150 degrees 

 for from twenty minutes to half an hour, then cooling and bottling or bottling hot 

 and cooling in the delivery container. Establishments equipped to pasteurize two 

 to three hundred thousand quarts of milk, and to wash and fill as many bottles within 

 a few hours each day, are to be found now in every large American city. 



" Certified " Milk is milk produced under such conditions of cleanliness of cows, 

 barns, attendants, freedom from disease, promptness in cooling and delivery, that 

 in America the milk commission or the county medical society will " certify " to the 

 public that the milk meets the bacterial and sanitary standard established for a milk 

 suitable for infant food. The making of machinery for the bottling of milk, washing 

 of bottles, pasteurization of milk and freezing of ice cream and manufacture of butter 

 on a large scale has recently assumed gigantic proportions. 



Butter Making. The demand for milk and cream for retail delivery and ice cream 

 manufacture has stopped the creamery butter-making in most territories tributary 

 by railroad to the large cities, especially in the eastern United States. The centrifugal 

 hand-separator is now found on a large proportion of the farms where butter is made, 

 and has made possible the recent development of the centraliser creamery, each of which 

 receives cream produced and separated on several thousand farms within two or three 

 hundred miles radius, in many instances superseding the skimming stations to which 

 the farmer hauled his milk and cream and from which he took home the skim milk. 



Moisture Test. The establishment in America of a Federal maximum moisture 

 content of 16% for butter has brought to the front the moisture test, and made pos- 

 sible its convenient determination. 



Artificial Buttermilk. The writings of Metchnikoff on the influence of lactic 

 acid bacteria in prolonging life by lessening the putrefactive fermentation in the intes- 

 tine has stimulated the production of artificial buttermilk under such trade names 

 as Fermillac, Heltho, Vitalc, Bacillac, Zoulak and others. They are made from skim- 

 milk, or that with a low fat content, soured to the point of coagulation of the casein 

 by the lactic acid produced by a combination of pure cultures of lactic acid forming 

 bacteria, such as Bacterium lacticum and Bacillus bulgaricus, after which it is thorough- 

 ly agitated to break up the curd and make a smooth product. 



Feeding Standards. German scientists first promulgated the idea of supplying the 

 animal body with the required constituents in definite proportion and in terms of com- 

 position of the feed, i.e. protein, carbohydrates and starch. Under the direction of 

 Dr. H. P. Armsby of the Pennsylvania State College, and in co-operation with the United 

 States department of agriculture, was built the first respiration calorimeter for accu- 

 rately determining the disposition of food eaten by animals, by recording and ana- 

 lysing all ingo and outgo of air, food, water and excreta. This work has resulted in 

 a method of indicating the relative value of foods and standards of daily requirements 

 in terms of net energy (i.e. power to do work) after deducting from total energy of feeds 



