FIRST LESSONS IN POULTRY KEETING. 113 



To the novice in this frame of mind comes the expert writer on scientific feeding, purporting 

 to give him in his science of feeding precise and exact instructions as to the feeding of fowls 

 for any and all purposes. 



This science of feeding is very interesting, and as long as certain essential things are dis- 

 regarded, seems very plausible. Let me state it briefly : 



The Modern "Science" of Feeding. 



The discussion of scientific feeding begins with the proposition that certain food elements of 

 different character are required to sustain life, promote, growth, and keep up the various 

 functional activities of the body ; and that the proportion of each of these elements required 

 can be ascertained and expressed in mathematical figures, which, in turn, may be taken by the 

 poultryman and applied in his practice. It is assumed that in this way he may arrive at sure 

 results and absolute economy in feeding. 



The Needs of an Animal Organism. 



The food which a fowl takes into its system serves these three purposes: 

 1. To build up and sustain the organism. 

 2. To keep up the warmth of the body. 



3. To furnish energy strength which is expended in -every movement. 

 Perhaps as the same classes of food elements serve the second and third purposes we can still 

 further simplify the statement by saying that the two principal functions of food are : 

 1. Nourishment. 

 2. Heat and energy. 



To provide for these two wants we have three kinds of food elements, technically known as 

 proteids, carbohydrates, and fats. 



These elements are found in varying proportions in the articles we use for poultry foods. 

 Without attempting a scientific description of them I will give the following plain definitions 

 suitable for the present purpose. 



Proteids (ov protein). Albuminous or nitrogenous matter occurring in different forms in 

 different kinds of food, but having everywhere the same essential qualities. In grains it is in 

 the form of gluten. In milk it is casein ; in meat and blood, fibrin ; in bones, gelatin. 

 Carbohydrates. Carbonaceous matter, principally starches. 

 Fats. May be regarded as highly concentrated, condensed carbohydrates. 

 These are the principal food elements. Besides them all foods contain some (and some a 

 great deal of) water, and most foods contain mineral and fibrous matter which are mostly 

 indigestible. 



The Theory of Scientific Feeding. 



The theory of scientific feeding is based on the assumed necessary relation of the needs of 

 the fowl to the food elements which are given it to supply those needs. 



Thus the scientific authority on poultry foods says that having ascertained just what food 

 elements, and in what proportions, were required to produce certain results with a certain 

 number of fowls, we are able from this data to formulate a rule which will apply universally. 

 Whether or not this is the fact we will inquire a little further on. 



The expert in scientific poultry feeding, following the lead of scientists in cattle (and in 

 human) feeding studies, makes use of two measurements of food values which he calls 

 nutritive ratio and potential energy. 



By nutritive ratio he means the ratio of the proteids or nitrogenous matter to the combined 

 values of the carbohydrates or starchy matter, and the fats, (the value of which are for the 

 purpose reduced to terms of carbohydrates). 



By the potential energy of a food he means its heating capacity, its fuel value, which he 

 expresses in calories per ounce. 



His science of feeding proceeds upon the principle that, having established standards of 

 nutritive ratio and potential energy as the proper standards, whatever combination of foods he 

 can make that will figure out this ratio and this heating capacity, will be a complete or balanced 

 ration, while a ration that will not figure out to such standards is an incomplete, ill balanced 

 ration. 



