ILLINOIS DAIRYMEN'S ASSOCIATION. 259 



Digestible Nutrients. 



The digestibility of the different constituents of feeds is of 

 great importance, as only that portion of feeding stuffs which 

 passes into solution during the process of digestion and is ab- 

 sorbed into the blood is of value to the animal. This portion of 

 the various feeds is known as the digestible nutrients. 



The difference between the total nutrients and the total di- 

 gestible nutrients is marked ; for example, by referring to feeding 

 tables we find that in 100 pounds of clover hay there are 12.3 

 pounds of protein, btit of this only 6.8 pounds are diegstible and 

 can be used to nourish the animal. The digestible nutrients are, 

 therefore, the only ones considered in making up rations. 



Table 1. — Digestible Nutrients Required Per Day for a 1,000 Pound Cow 

 for Maintenance and Following Yields. 



Much careful study and investigation has been devoted to 

 the question of determining amounts of digestible protein, car- 

 bohydrates, and fat needed for cows of different weights and vary- 

 ing yields. To Professor T. L. Haecker belongs the credit of 

 securing the data from which the following table has been com- 

 puted. 



Carbohy- Nutri- 



Protein. drates. Fat, tive 



It). It). lb. ratio. 



For maintenance 7 7. .1 1:10.3 



10 lb. millc 3% fat 1.10 8.81 .24 1:8.5 



10 lb. milk 4% fat 1:17 9.16 .26 1:8.4 



10 lb. milk 5% fat 1.24 9.51 .29 1:8.2 



20 lb. milk 3% fat 1.49 10.62 .37 1:7.7 



20 lb. milk 4% fat 1.63 11.32 .42 1: 7.5 



20 lb. milk 5% fat 1.77 12.02 .47 1: 7.4 



30 lb. milk 3% fat 1.89 12.43 .51 1:7.2 



30 lb. milk 4% fat 2.10 12.48 .58 1:7.1 



30 lb. milk 5% fat 2.31 14.53 .66 1: 7.0 



40 lb. milk 3% fat 2.29 14.24 .64 1:6.9 



40 lb. milk 4% fat 2.57 15.64 .74 1:6.8 



40 lb. milk 5% fat 2.85 17.04 .84 1:6:7 



50 lb. milk 3% fat 2.68 16.05 .78 1:6.7 



50 lb. milk 4% fat 3.03 17.80 .90 1: 6.6 



50 lb. milk 5% fat 3.38 19.55 1.03 1:6.5 



60 lb. milk 3% fat 3.08 17.86 .92 1:6.5 



60 lb. milk 4% fat 3.50 19.96 1.07 1:6.4 



60 lb. milk 5% fat 3.92 22.06 1.22 1:6.3 



