230 Milk and Its Products. 



should be fed in connection with them, if they are 

 used to the best advantage. When economically- 

 fed to 3'oung pigs and calves, skimmed milk and 

 buttermilk may be made to return about fifteen cents 

 per hundred weight, and whey about one- third less. 

 These products are of value for food in proportion 

 as the milk sugar has not been changed to lactic 

 acid. They may be fed in unlimited quantities with- 

 out ill results upon the health of the animal, ex- 

 cept that occasionally when the milk is very sour, 

 or when fermentations other than lactic have set 

 in, derangements of the digestive organs, diarrhoea, 

 etc., sometimes occui\ It is, therefore, advisable that 

 all of these products should be fed in as fresh a con- 

 dition as possible, and it has been found in many 

 instances that the custom of sterilizing or partially 

 sterilizing the skimmed milk or whey at the factory, 

 by injecting a jet of steam into it until the whole 

 is heated up to about 180° F., is practical, and is fol- 

 lowed by beneficial results. 



Dried casein, paper sizing. — The casein of milk 

 in a dry form is useful in certain manufacturing 

 process, and has been found to be particularly val- 

 uable for the preparation of sizing for paper. The 

 manufacture of dry casein for this purpose has 

 come to be an important means of utilizing 

 skimmed milk in many creameries, and its prepara- 

 tion is comparatively simple. The skimmed milk is 

 collected in a vat and the curd precipitated with a 

 mineral acid. A mixture of acetic and sulphuric 

 acids is commonly used, and from % to 1 per cent 



