358 AGRICULTURAL CHEMISTRY 



amount of non- nitrogenous to nitrogenous compounds, 

 while a narrow nutritive ratio means a small amount of 

 non-nitrogenous to nitrogenous compounds. 



To calculate the nutritive ratio, first determine the 

 pounds of digestible protein in the food used, then the 

 pounds of digestible carbohydrates, etc. Multiply the 

 pounds of digestible ether extract by 2.2 because the fat 

 produces 2.2 times as much heat, consequently is con- 

 sidered 2.2 times more concentrated than the nitrogen - 

 free extract compounds. Add the digestible fiber, nitro- 

 gen-free extract and corrected ether extract and divide 

 the sum by the digestible protein; the result is the nutri- 

 tive ratio. The nutritive ratio of the ration given is 6.57 

 (0.6 X 2.2 = 1.32) (1.32+ 11.56=12.88) (12.88-^-2.07 

 = 6.02). 



482. Caloric Value of Rations. The caloric value of 

 a ration is determined by multiplying the pounds of 

 digestible ether extract by the factor 4225 and adding this 

 to the number secured by multiplying the sum of the di- 

 gestible protein and carbohydrates by 1860. As used in 

 the calculation of rations, the carbohydrates include the 

 nitrogen- free extract compounds and the digestible fiber. 

 The term carbohydrates is used in the broad rather than 

 the restricted sense. 



Problem i. Calculate a ration for a i2oo-pound horse at light 

 work. Use any foods desired. 



Problem 2, Calculate a ration for a I2oo-pound horse at heavy 

 farm labor. 



Problem j. Calculate a ration for a pig weighing 100 pounds. 



Problem 4. Calculate a ration for a pig weighing 250 pounds. 



