INVESTIGATIONS AT THE COLLEGE 55 



their exact feeding value, but that the degree of their 

 digestibility exerted a controlling influence on their 

 qualification to support animal life. 



Grouven conducted a series of experiments (1860- 

 1864) which have revolutionized the science of stock- 

 feeding. He concluded that a rational and economical 

 system of feeding farm stock required the following in- 

 formation: 'First, how much nitrogenous matter, 

 how much carbohydrate and fatty matter, and how 

 much mineral substance in a digestible form does 

 each kind of animal require, not only in its various 

 stages of growth, but also for every purpose it is 

 designed to answer? Second, how much of each of 

 these four groups of substances is present in a di- 

 gestible state hi our various articles of fodder?' Aside 

 from his own contributions to this subject, Grou- 

 ven attempted to bring the valuable results of pre- 

 vious scientific research within reach of the practical 

 farmer. 



Dr. Goessmann then explained the terms used in 

 reporting the results of his analysis of different kinds 

 of corn. All plants, including most of our common 

 articles of fodder, contain four groups of nutritive 

 compounds : protein or nitrogenous substance, carbo- 

 hydrate or non-nitrogenous substance, fats, and min- 

 eral constituents. These are present in absolutely 

 and relatively varying quantities in each plant and 

 part of plant, and serve in absolutely and relatively 

 different proportions for the support of animal life. 

 The nutritive ratio of a fodder substance is the numer- 

 ical relation of its nitrogenous substance compared 



