138 AGRICULTURE. 



not alone upon the food, but upon the breed, 

 individuality, and condition of the animal fed. 



These standards are excellent as a basis for 

 feeding and for comparison. No stockman 

 should omit the results of his own experience 

 if he has kept an accurate record of feeds and 

 their results as an element in deciding upon a 

 suitable ration for different animals at different 

 stages of development or different requirements 

 of work. 



4. Nutritive Ratio. The ratio between the 

 protein and the heat-producing elements (car- 

 bohydrates and ether extracts) for any kind of 

 food, or combination of foods, is called the nu- 

 tritive ratio. For example, in the daily food 

 required 20 pounds dry matter for a horse 

 doing light work, the amount of digestible pro- 

 tein is 1.5 pounds; carbohydrates, 9.5 pounds; 

 ether extract, .4 pounds. Multiplying the num- 

 ber of pounds of ether extract, .4, by 2.4, or its 

 heat value, the result is .96 pounds ; this, plus 

 the carbohydrates, 9.5 pounds, is equal to 10.46 

 pounds. Dividing the 10.46 pounds of heat- 

 producing elements by the number of pounds of 

 protein, 1.5, the result is /:; therefore, the nu- 

 tritive ratio of this food is 1:7. 



EXERCISE 6. (a) What is the nutritive ratio of a food 

 containing .7 pounds of protein, 8 pounds of carbohy- 

 drates, and .1 pound ether extract? 



(b) If the nutritive ratio of a food is 1:7.7, a "d the 



