BUREAU OF ANIMAL INDUSTRY. 99 



CHEESE. 



A special effort lias been made to apply the new methods of making 

 the Swiss type of cheese on a commercial basis. In most of the fac- 

 tory trials this method was a success and resulted in the production 

 of cheese of uniformly high quality. Before extensive work can bo 

 done witli factories, however, a practicable means of distributing 

 eye-forming cultures must be devised. The question of the relation 

 of the culture and formation of eyes has been established beyond 

 question. 



In an attempt to introduce into this country the manufacture of 

 various cheeses now imported, cheeses of the Camembert and Roque- 

 fort varieties were made successfully on a commercial scale at 

 the Grove City creamery, but so far none have had a fair trial on 

 the market. 



UTILIZATION OF CBEAMERY BY-rRODUCTS. 



Considerable work has been done on the development of casein 

 for use in waterproof glue, and a casein of low ash and acid has 

 already been produced. 



A method of producing casein from buttermilk is also being 

 worked out. Using a solvent to extract the fat from the buttermilk, 

 small lots of casein have been made, and this product was found to 

 be of general good quality and low in fat and ash, but had the 

 objection of dissolving slowly. 



Work is now in progress with the object of developing a method 

 of utilizing whey as a human food. It is probable that whey rep- 

 resents a greater actual loss of food than skim milk, because its 

 feeding value is not generally recognized. Primost and Ricotta 

 cheeses, which are made from whey, were produced at the Grove 

 City creamery, but the demand has been limited. The use of these 

 cheeses might be extended if their value for cooking could be brought 

 to the attention of housekeepers. Investigations have also been begun 

 on the utilization of whey solids in the form of poultry feed. 



SILAGE INVESTIGATIONS. 



Studies on the value and composition of corn plants and sunflower 

 plants for silage have shown that good silage can be made from the 

 latter as well as the former. Various tests have been made on the 

 composition of these crops at different stages of maturity, but no 

 correlation has been established between the composition of the 

 plants and the quality of the silage. 



WAR ACTIVITIES. 



A considerable part of the time of the laboratory staff was spent 

 in lending aid in preparing material necessary to carry on the war. 

 Assistance was rendered to the Army Medical Corps by providing 

 laboratory facilities for drying typhoid vaccine. Probably the most 

 important work, however, was the developing on short notice of a 

 method of making casein of more than ordinary purity. Tliis was 

 necessary in the manufacture of the waterproof glue essential to the 

 manufacture of airplane parts. Another war problem worked out 



