New York Agricultural Experiment Station. 117 



on the milk due to changes of the amount of phosphorus in the 

 ration. Their tables justify such a conclusion; for in only one 

 instance is there such a relation, namely in the fifth period of experi- 

 ment I, where the following quantities are recorded: 



Phosphorus fed 83 . 3 21 . 4 80 . 7 grains 



Fat-free sohds 8.3 8.6 8.2 percent 



If a change is induced in the composition of the milk by the varia- 

 tion of the phosphorus of the diet, we would expect this to affect 

 the casein, but in all four experiments the casein varies but little 

 and in no definite relation to the phosphorus intake. The other 

 organic phosphorus compound of the milk, lecithin, was not deter- 

 mined. If we return to the total phosphorus and recalculate these 

 amounts to a fat-free milk, we obtain the following percentages : 



Period I II III IV V 



Phosphorus 0.107 0.115 0.108 0.113 0.106 



This makes a maximum difference of 0.009 per ct. Similar cal- 

 culation of the data from the experiments reported in Technical 

 Bulletin No. 1, gives: 



Experiment I II HI 



, ' , , > , , ' , 



Grams P in rations 12 8 78.7 16.0 83.3 21.4 37.0 18.0 37.0 20.0 77.0 16.0 

 Percentage of P in 

 fat-free milk.... 0.090 0.089 0.0b6 0.083 0.090 0.108 0.108 0.107 0.110 0.104 0.110 



or a maximum difference for the two animals of only 0.032 per ct, 

 and for the one animal, " Nancy," used in experiments II, III and 

 IV of only 0.011 per ct. which may well be considered within the 

 limits of unavoidable error. This suggests that the phosphorus 

 contents of the solids vary with the individual animal and not 

 with the phosphorus content of the rations fed. 



Until more evidence to the contrary has been brought forth we 

 may safely assume that the fat is the only milk constituent changed 

 by alteration of the phosphorus content of the rations, and that 

 there is a definite relation between the phosphorus supply and the 

 yield of milk and butter fat. 



It has not been conclusively proven that all the changes noted 

 in the milk production are due specifically to phytin phosphorus 

 but the evidence warrants the assumption that this substance is in 

 whole or in part responsible for the phenomena observed. When 

 further experiments which have been planned for this series are 

 completed it is hoped that the evidence will show more definitely 

 just what part the phytin salts as a whole, or its cations and anion 

 will play in the physiological functions of the milk cow and how 

 the associated bran extractives may modify this action. 



INFLUENCE OF PHOSPHORUS ON EXCRETA 



There were in this experiment no gross changes in the nature of 

 the dung like those reported in the previous experiment but changes 



