230 POULTRY BREEDING AND MANAGEMENT 



puted as follows : Suppose the ration is 10 pounds wheat, 

 3 pounds oats, 2 pounds bran and 1 pound beef scrap. By 

 referring to the table of composition of feeds, page 227, it 

 will be found that wheat contains 11.9% protein; so that in 

 10 pounds wheat there are 1.19 pounds protein ; it contains 

 73.7% carbohydrates, and in 10 pounds there are 7.37 

 pounds carbohydrates. The percentage of fat is 2.1, or 

 0.21 pound fat in 10 pounds wheat. Figuring the other 

 foods in the same way, we get the results shown in the 

 following table : 



10 Ibs. 3 Us. 3 Us. 1 Ib. beef 



To get the nutritive ratio, multiply the total fat by 2*4 

 (0.57X2 1 / 4=1.28) . Add this to the carbohydrates (10.76+ 

 1.28=12.04). Divide this by the total protein (12.04-^2.49) 

 and we get the nutritive ratio of 1 :4.8. In other words, 

 this ration contains one pound of protein to 4.8 pounds 

 carbohydrates and fat. This is not given as a good ration, 

 but simply to show how the nutritive ratio is computed. 

 In point of fact, this method of computation is not correct 

 because it is figured on the total nutrients, not on the 

 amount actually digestible. 



Digestibility of Poultry Foods. In the above compu- 

 tation it is seen, for example, that there are 1.19 pounds 

 of protein in 10 pounds wheat, but according to Henry's 

 compilation of digestion coefficients for livestock, there is 

 only 0.88 pound digestible protein in 10 pounds wheat. 

 The amounts digested are shown in the following table, 

 using the standard coefficients for livestock; 



