192 THE FEEDING OF ANIMALS 



Per cent 

 deposited 

 Corn proteins 90 per cent, oil meal proteins 10 per cent . 31 

 Corn proteins 75 per cent, oil meal proteins 25 per cent . 37 

 C!om proteins 60 per cent, oil meal proteins 40 per cent . 32 



Those proteins are most efficient, evidently, whose 

 building-stones correspond most nearly in proportion to 

 those of animal proteins. 



276. Nutritive value of the gelatinoids.— The gelati- 

 noids which belong to the class of non-proteins cannot 

 be regarded as taking the place of proteins. It has been 

 found that they protect protein from cleavage and thus 

 make a minimum protein-supply more efficient but they 

 do not function in the synthetical processes as the true 

 proteins do. Gelatin also is lacking in certain building- 

 stones, namely tyrosine, cystine, and tryptophane. This 

 consideration of the protein compoimds on the basis of 

 their building-stones is a new and interesting point of 

 view and leads to the conclusion that those proteins are 

 most efficient for constructive piu-poses whose buUding- 

 stones correspond in kind and proportion most nearly to 

 those of the proteins in the animal body. 



277. Synthesis in the animal of phosphorus-bearing 

 proteins. — One interesting question which has been con- 

 sidered is whether the nucleo-proteins and phospho- 

 proteins which are found so abundantly in eggs and in 

 milk must be supplied as such in the food, or whether 

 they may be built up in the animal from the simple pro- 

 teins and phosphates. If we could learn that the food 

 must contain these peculiar proteins all ready for use, 

 then we would have a valuable suggestion for feeding 

 cows and poultry. It now seems that this is not the case. 

 The sea salmon, which, during its stay up the river, is 

 believed to take no food, undoubtedly produces large 



