Selecting Feeding Stnffs 275 



grains, and oat feeds is on the average only about 62 

 per cent. Oats are nearly one-fonrtli less digestible 

 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 nutritive value of commercial feeds very materially. 

 Farmers should base their judgment of the value 

 of feeding stuffs primarily upon the i)roportions o£ 

 digestible dry matter which they contain. This method 

 will probably allow the closest approximation to rela- 

 tive values of any. It is certainly more accurate than 

 a comparison of the proportions of total dry matter. 

 A hundred pounds of corn contains even less dr}^ 

 matter than the same weight of oat feed, but the di- 

 gestible material of the former is over 30 per cent in 

 excess of that in the latter. It is to be remembered, 

 however, that comparisons of this kind can only be 

 instituted between feeding stuffs of the same class. 

 The relative values of oil meal and corn meal cannot 

 be ascertained in this way, neither can those of tim- 

 othy hay and corn meal. 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 identical in the two cases. Diges- 

 tible material, which is 40 per cent protein, cannot be 

 measured by digestible material, which is only 10 per 

 cent protein. Neither can we so compare timothy hay 

 and corn meal, for while the proportions of protein 

 and non- protein compounds may not be so very differ- 

 ent in the two, the nitrogen -free compounds are 



