VALUATION OF FEEDING-STUFFS 287 



about 62 per cent. Oats are nearly one-fourth less digesti- 

 ble than corn, barley, or rye. The refuse products known 

 as the oil meals are less digestible than the gluten feeds 

 and meals, due, doubtless, to the hulls contained in the 

 former. These facts are important and affect the nutri- 

 tive value of commercial feeds very materially. 



384. Values based on digestibility. Farmers should 

 base their judgment of the value of feeding-stuffs pri- 

 marily upon the proportions of digestible dry matter which 

 they contain. This method will probably allow as close 

 an approximation to relative values as any which it is 

 feasible for the farmers to use now in practice. Doubt- 

 less "production" values (see Par. 263) will ultimately 

 offer a closer comparison. It is certainly more accurate 

 than a comparison of the proportions of total dry matter. 

 A hundred pounds of corn contains even less dry matter 

 than the same weight of oats, but the digestible material of 

 the former is over 20 per cent in excess of that in the latter. 

 It is to be remembered, however, that comparisons of 

 this kind can be instituted only between feeding-stuffs of 

 the same class. The relative values of oil meal and corn 

 meal cannot be ascertained in this way, neither should 

 the relative values of coarse feeds and the grains be so 

 compared. We should not pay for oil meal and corn 

 meal on the basis of the quantities of digestible nutrients 

 which they furnish, because the nutrients are not identi- 

 cal in the two cases. Digestible material which is 40 per 

 cent protein cannot be measured by digestible material 

 which is only 10 per cent protein. 



385. Digestibility of various feeds. The following 

 table shows the digestible material in 100 pounds of 

 various feeding-stuffs, as calculated from average com- 

 position and digestibility. In the case of hays, the water- 



