NUTRITION. 305 



parts should be separated in milling flour in order to use the entire 

 grain most profitably. 



This work has demonstrated that the proteins of the entire kernel 

 are adequate for promoting normal growth, provided the animal can 

 be induced to eat enough of them. The endosperm proteins, on the 

 contrary, are much less efficient when compared on their nitrogen 

 basis. The proteins of the embryo and of the bran (provided the 

 animal is able to digest the latter) are much more efficient in promoting 

 growth than are those of the entire kernel. For the maintenance of 

 mature animals somewhat more of the endosperm proteins than of 

 those of the whole wheat or the embryo is required, though these 

 differences do not appear to be so great in the case of maintenance as 

 where growth is involved. 



When the wheat proteins are supplemented with proteins from 

 meat, milk, or eggs, less total protein is required for maintenance or 

 for normal growth than when the wheat kernel forms the sole source 

 of protein. Since the proteins of meat, milk, or eggs supplement the 

 proteins of patent flour, the latter is mostly used in this country under 

 conditions which permit an economical utilization of its protein. 

 Although the proteins of the embryo and bran also supplement those 

 of the endosperm, the entire kernel does not contain enough protein 

 in these parts to render the endosperm proteins as efficient in pro- 

 moting growth as when they are supplemented with the animal 

 proteins together with which they are commonly eaten. Hence, from 

 the protein standpoint nothing is to be gained by grinding the entire 

 kernel, except where patent flour forms an excessive proportion of 

 the diet; and in these cases the protein deficiencies of the flour are 

 more effectively met by including a moderate quantity of animal 

 protein in the diet. 



Since most farm animals can easily digest the nutrients in bran and 

 embryo, and since the proteins of these parts of the wheat kernel 

 doubtless supplement those of the vegetable foods to which the wheat 

 by-products are ahnost always added in agricultural practice, it seems 

 certain that the methods of using wheat which prevailed before the 

 war are economical. Although food fed to farm animals is returned in 

 much smaller quantity in the form of human food, it must be remem- 

 bered that the meat, milk, and eggs thus produced render the protein 

 in the 70 per cent of wheat that goes into patent flour of practically the 

 same nutritive value as that furnished by the more expensive animal 

 proteins, and of far more value than if eaten in the form of either 

 entire wheat or graham flour without a suitable protein supplement. 



50 to 60 per cent of patent flour in an otherwise adequate diet 

 furnishes barely sufficient vitamine to promote satisfactory growth, 

 and 30 to 40 per cent is required for maintenance. On the other 

 hand, 15 to 20 per cent of the entire kernel, or as little as 2 to 5 per 



