164 FEEDING FARM ANIMALS 



important, since water can be supplied. These elements 

 exist in varying degrees in plants and in the same plant at 

 different stages of development, and similarly they differ in 

 the degree of the digestibility which they possess. The de- 

 gree in which they are present and also the degree of the 

 digestibility which they possess, can only be determined by 

 chemical analysis, hence the necessity for tables of feeding 

 stuffs, which the feeder may consult when preparing or 

 feeding foods. The proportions in which these elements 

 should be supplied to animals also varies with the class of 

 the animal, the age, the performance and the object for 

 which it is kept. The adaptation of food to the needs of the 

 animals to which it is to be fed virtually constitutes the 

 great art of feeding. 



I^or convenience in reference, certain definitions per- 

 taining first to the feeds themselves and second to the meth- 

 ods of blending or compounding them for feeding, have 

 come into common use. These are all considered in Chap- 

 ter X. The definitions which pertain to feeds include the 

 terms: (i) Food nutrient; (2) food factor or feeding stuff; 

 (3) food or feeding ration and (4) table of feeding stuffs. 

 Those which pertain to the blending or compounding of 

 feeds, include the terms: (i) Nutritive ratio; (2) feeding 

 standard and (3) table of feeding standards. Familiarity 

 with these terms and the ability to reduce to practice what 

 is implied in them, should prove helpful to all persons en- 

 gaged in growing stock. 



Food nutrient. A food nutrient is any single chem- 

 ical compound capable of being assimilated by the body, for 

 the purpose of producing new tissue, either for new growth 

 or to replace that which is worn out. The body is com- 

 posed of: (i) Nitrogenous organic substance; (2) non- 

 nitrogenous organic substance and (3) mineral substance. 

 Since a food nutrient in order to permit of easy assimila- 

 tion, must in its composition be identical with the substances 

 normally found in the body, the nutrients may be classified 

 very similarly to the classification of the substances of the 



