The Pennsylvania State College 

 Agricultural Experiment Station 



BULLETIN No. 105 



INFLUENCE OF TYPE AND OF AGE UPON THE 

 UTILIZATION OF FEED BY CATTLE 



HENRY PRENTISS ARMSBY AND J. AUGUST FRIES 



In a permanent system of agriculture, the essential function of 

 domestic animals is to utilize for the benefit of man the solar energy 

 stored in the inedible products of the soil, such as hay, straw, and 

 other forage crops, or in the host of by-products arising in the pre- 

 paration of farm crops for use as human food. When these inedible 

 substances are consumed by domestic animals a portion of this 

 energy is recovered, in part as work but largely in the form of 

 materials serving for the nutrition of man. 



The Institute of Animal Nutrition of The Pennsylvania State 

 College, in co-operation with the Pennsylvania Experiment Sta- 

 tion and with the Bureau of Animal Industry of the United States 

 Department of Agriculture, is engaged in a study of those scientific 

 principles which underlie and condition the successful economic 

 transformation by the animal of waste products into human food. 

 The investigations in progress relate to three general classes of 

 questions : 



First: How do different feeding stuffs compare with each 

 other as to their content of energy and the proportion of it which 

 may be rendered available to man through the agency of domestic 

 animals? 



(3) 



