THE FEEDING OF ANIMALS 39 



except the water, and to speak of them collectively as dry- 

 matter, and not with respect to their total weight. Ash is also 

 eliminated, and the remaining three constituents are called nu- 

 trients. Each of these groups has its part to perform in the nu- 

 trition of animals, the function of one being different from the 

 others. There are a few foods containing these several constitu- 

 ents in the proper proportions to meet the needs of the animal, 

 but in most foods there is an excess of one and a deficiency of the 

 others. This makes it desirable to add two or more foods of 

 different composition in order to supply the proper balance for 

 the best development of the animal. 



Water. — ■ Water is present in all foods, even the driest. It 

 varies widely in different foods, running as low as 8 or 10 per cent 

 in the case of grains or concentrates, such as corn, oats, or cotton- 

 seed meal, and dried brewers' grains, to 85 or 90 per cent in the 

 more watery foods, as silage, roots, tubers, and the like. Even 

 dry hay varies considerably in this respect, alfalfa containing as 

 low as 9 per cent and some clovers as high as 20 per cent. Water 

 not being a nutrient, its presence or absence is an important fac- 

 tor in determining the usefulness and therefore the value of afood. 



Ash. — Ash or mineral matter is present in all plant food, 

 although it forms but a small part, shelled corn containing only 

 1.5 per cent, and alfalfa, one of the highest, containing only 8 

 per cent. The leaves and the region of the germ in grain contain 

 the most ash. The animal secures the ash from the food directly 

 by transfer. Most plants contain sufficient ash to meet the 

 needs of the animal, corn and certain prepared foods being the 

 only exceptions. In young animals, because of the large bone 

 development that is taking place, in milk and egg production 

 and the like, it is of special importance to have sufficient 

 mineral matter supplied by the food. 



Protein. — Of the three nutrients — protein, carbohydrate^, 

 and fats — the protein is considered to be the most important. 

 This is. perhaps due to two factors; first, protein is absolutely 



