PRINCIPLES OF FEEDING 207 



udder ; the beef cow and the hog lay the fat on over the 

 muscles. 



Fat. Some foods, such as cotton-seed meal, linseed 

 meal, nuts, etc., contain a considerable quantity of oil or 

 fat. This is used by the animals for food in the same way 

 and for the same purpose as the carbohydrates. It is, 

 however, about two and one-fourth times as valuable in 

 producing heat as the same quantity of carbohydrates. 



EXERCISES. 



1. Make a list of ten animal foods valuable chiefly for 

 protein. 



2. Make a list of ten foods valuable chiefly as carbo- 

 hydrates. 



3. Consult the Table on pages 257, 258 and arrange the 

 foods in each list according to the relative amounts of 

 protein, carbohydrate, and fat in each. 



Feeding Standards. It is evident from the lists that 

 you have made that the most expensive foods are those 

 valuable chiefly for the protein which they contain. The 

 economical farmer will feed these foods as sparingly as 

 possible and still produce the results he desires. It has 

 been found by careful testing just what proportion of 

 protein and carbohydrates it is best to feed an animal. 

 For instance, it has been found that, for an average dairy 

 cow, about six times as much carbohydrates as protein 

 should be fed for the best results. This relation is usu- 

 ally expressed as a ratio, as i to 6 or 1 : 6, and is called the 

 nutritive ratio. This means that, for every pound of 

 protein, six pounds of carbohydrates should be given. 



