The following is from Bulletin 43, Washington Agricultural College, by- 

 Prof. W. J. Spillman:— 



" Considerations in Compounding Rations. 



"Amount. In determining the amount of feed an animal ought to have, 

 a number of things must be taken into consideration. Regard must be had 

 with reference to what the animal- is to do with its food. 



" Let us first consider the case of a mature animal which is neither being 

 fattened for the market, giving milk, producing wool, or doing work of any- 

 kind. Such an animal needs food only to supply the heat of the body, the 

 small amount of energy required for the necessary activities of the body, and 

 to repair the small waste of body material going on at all times. Such an 

 animal would naturally need very little protein, and not a large quantity of 

 carbohydrates and fat ; and the amount of food required would depend almost 

 entirely on the size of the animal. Under such conditions an 800-pound 

 animal would need half as much food as one weighing 1,600 pounds. 



" A ration intended for animals under the condition just described is called 

 a maintenance ration. It is supposed to maintain a mature, idle animal in 

 substantially its present condition, when neither growth, increase of fat, milk, 

 wool or work is required of it. 



" Suppose now that the animal in question is a young, rapidly growing 

 one. This animal should have, in addition to its maintenance ration, enough 

 to supply the heavy demand for materials with which to make new body 

 material. Such an animal should not only have more food than a mature, 

 idle animal of the same size, but that food should have a larger proportion 

 of protein in it, because it is protein which builds up the tissues. The 

 activities of a young animal are also usually greater than those of older 

 animals, and the body temperature slightly higher. Hence they need slightly 

 more carbohydrates and fat than older animals in proportion to their weight. 



" In the case of animals that are expected to lay on fat it is plain that 

 they should have large amounts of carbohydrates and fat, in addition to their 

 maintenance ration. But since fat animals that have large proportions of 

 lean meat amongst the fat are much more desirable for meat-making pur- 

 poses than those that are simply a ball of fat, and since an animal that is 

 to continue a long, rapid growth must develop large, strong bones to carry 

 its heavy carcass, it is also plain that fattening animals should have liberal 

 supplies of protein, especially in the earlier part of the fattening period, when 

 growth of frame is so desirable. It is only during the finishing up period 

 that the amounts of carbohydrates and fat should run considerably ahead of 

 the already large supply of protein. 



" In the case of cows giving milk, it should be remembered that the casein 

 and albumen of milk are made from protein; while the butter fat and milk 

 sugar are made from carbohydrates and fat. It is plain, therefore, that a 

 milk cow needs, in addition to her maintenance ration, a quantity of protein, 

 carbohydrates and fat proportionate to the amount of casein, albumen, fat 

 and sugar she is producing. In fact the production of milk actually takes 



