I4t>y FEEDS AND FEEDING 



domestic animals) there is a much greater ratio of organic to inorganic phos- 

 phorus, than in the bodies of these animals. Therefore each time it is 

 necessary to increase the total quantity of phosphorus of a ration this re- 

 sult can be completely achieved by giving the phosphorus in the form of 

 inorganic compounds. 



It appears improbable that, for young or adult animals, any diet what- 

 ever, composed of natural foods and satisfying the nitrogen requirement, 

 will fail to furnish enough phosphorus to maintain the equilibrium of this 

 element. It is however certain that many rations composed of common 

 foods do not contain the quantity of phosphorus necessar\' to assure the ma- 

 ximum assimilation of this element and the maximum development. 



The results of the experiments indicate that the popsibilit}'^ of influenc- 

 ing to a practical extent, the relative development of the tissues and organs 

 of domestic animals by adding isolated compounds of phosphorus to the ra- 

 tion, is probably limited to the density and strength of the bones. How- 

 ever, the increase of the resistance and density of the bones obtained b}' 

 adding phos])horus compounds to the normal diet is accompanied by only 

 a 3mall possible increase in the external dimensions. 



In order to increase the strength of the bones of growing animals, the 

 most practical form in which to administer the phosphorus for this purpose 

 is probably any preparation of bone readily eaten by the animals. Precipi- 

 tated bone phosphates are readily taken by all kinds of farm stock. 



The diets experimented with were deficient in phosjjhorus and calcium 

 but the animals possessed quite a limited tolerance towards each of these 

 elements in the form of their pure salts. The addition of marked (juantities 

 of calcium carbonate always produced digestive troubles ; although the de- 

 ficiency in phosphorus was such that the bones were quite insufficiently 

 nourished, it was not possible to administer more than 25 to 40 per cent of 

 the total phosphorus in the forms it was desired to study. The attempt 

 to increase the mineral base of the rations by the addition of potassium 

 and sodium citrate Were no more successful. 



1089 - The Influence of the Nature of the Diet on the Retention of Protein. — 



UMEDA N"., in Biochemical Journal, Vol. X, No. 2, pp. 245-2.S3. I,oiid(iii, Jinu- igifi. 



The question of the capacity of the organism to store protein has always 

 been one of considerable interest and although it is highly probable that 

 such a storing is a normal process, the critical conditions for its occur- 

 rence have not ^^et been fully elucidated, largely owing to the fact that 

 the amount of information available from nitrogen equilibrium studies is 

 small and its value difficult to assess. Still by the use of the method of 

 superimposition results of importance can be obtained without recourse 

 to such favouring conditions of storage as muscle work, growth or inani- 

 tion, all of which conditions introduce secondar}' factors which render the 

 interpretation of the data more difficult. 



In the course of another investigation Tsuji (1915) found that the 

 degree of retention of superimposed protein varied (i) with the nature of 

 the standard diet, and (2) with the nature of the protein superimposed. 

 As these experiments were, as regards the superimposition, only of one 



