48 FEEDING FARM ANIMALS 



is needed only to repair waste. So also it must have 

 enough protein to supplement the ash in building the 

 framework and in covering it with the requisite muscle. 

 Where either or both are lacking the development will not 

 be of the highest order. Carbohydrates are needed to 

 furnish the requisite heat and fat which the animal re- 

 quires. They are needed in less proportion when it is 

 young than when it grows older, for the reason first, that 

 the machinery of digestion runs more rapidly near the 

 birth period and consequently generates more heat in 

 proportion to the amount of food consumed, and second, 

 that during the period of growth much muscle is wanted 

 rather than much fat. It is very evident, therefore, that 

 the ration suited to a mature animal at rest should con- 

 tain more of carbohydrates relatively and less of protein 

 than would be suited to a young animal 



The objects for which animals are fed are equally insis- 

 tent in their demand for variation in the food given to them. 

 The calf that is being prepared for veal calls for food that 

 is rich in fat, such as whole milk or its equivalents, that 

 grown for being fattened at a later period or for milk 

 production calls for food with but litle fat in it, such as 

 skim milk furnishes. The animal grown for baby beef, 

 must have more of carbohydrates in its food than that grown 

 for being fattened later. Likewise the animal that is 

 giving milk must be given more of protein and less of 

 carbohydrates than would suffice for the same animal 

 while being fattened. Similarly, illustrations could be 

 multiplied of the necessity for variation in the food 

 nutrients in feeding all classes of domestic animals kept 

 on the farm. 



Foods not in equilibrium. In some instances it may 

 be advantageous viewed from the standpoint of profit to 

 feed foods out of balance, that is to feed an excess of car- 

 bohydrates in some cases and an excess of protein in 

 others. This may happen when some food factor, rich 



