156 EXPERIMENT STATION. [Jan. 



low coefficient (see present red wheat protein coefficient, and 

 average protein coefficients for maize) is due largely to the 

 above-mentioned cause. ^ A further study of the coefficients 

 of wheat, barley and corn, as given on the previous pages, 

 shows the extract matter to have practically the same degree 

 of digestibility.^ 



On the basis of composition and of the digestion coefficients 

 secured, the white variety of wheat is shown to be some 9 

 per cent, more valuable than the red. Whether this would 

 hold true as a general nde is not known. Other things being 

 equal, the higher the protein content of the wheat the more 

 valuable it is. 



Taking the value of all the ingredients into consideration 

 (protein, fiber, extract matter and fat), an average quality 

 of " feed barley " appears to be about as valuable as an 

 average quality of white wheat, and both grains figure slightly 

 more valuable than maize (8 per cent.). Kellner ^ considers 

 these three grains to have very nearly equal relative values, 

 and as sources of carbohydrates this estimate must be correct. 

 Brooks ■* has called attention to the fact that, with a plentiful 

 supply of animal protein, corn gives rather better results 

 than wheat for egg production, and at less relative cost. 

 In view of their composition and digestibility, it would seem 

 as if there were no reason to expect any particular difference 

 in the feeding effect of these two grains. It is possible, 

 however, that the energy required for the digestion of the 

 wheat might be greater than that required to digest the corn. 

 It is well known that poultry are particularly fond of corn 

 and moderately so of wheat, but do not care especially for 

 barley. This fact should not be overlooked in comparing the 

 relative merits of corn, wheat and barley for this class of 

 stock. 



1 For every 100 grams of dry matter fed, a reasonably definite amonnt of nitrogenous 

 metabolic by-products are egested, mixed with the faeces, whether the ration is rich or 

 poor in protein. It follows, therefore, that the smaller the amount of protein in the 

 total ration the smaller will be the amount of protein left (digested) after these by- 

 l)roducts which are included in the faeces have been deducted. 



- The digestion experiments thus far made with poultry show the dry matter in com 

 to be H7, protein 84 and extract matter 92 per cent, digestible; and in wheat dry matter 

 84, in'otein 77 and extract matter 89 per cent, digestible. In other words, poultry digest 

 the two grains to about tlie same extent as sheep. 



3 Loco ciUito, page hfA. 



* Eighteenth report or this station, page 152. 



