I9I2] 'Alfred P. Lothrop 163 



10. A study of the metabolism and physiological effects o£ 

 certain phosphorus Compounds in milk cows. Anton Richard 

 Rose. (New York Agricultural Experiment Station, Geneva, 

 N. Y.) The phosphorus requirement of a cow, aside from the 

 milk phosphorus, would seem from the results of this experiment 

 to be about 26 mg. per kilo of body weight. When the phosphorus 

 supply is less than this amount, the physiological functions are con- 

 tinued at the expense of the phosphorus previously stored in the 

 tissues. Storage takes place when a greater amount than that indi- 

 cated above is ingested. When the ingested insoluble phosphorus 

 did not exceed 14 grams per day, there was approximate regularity 

 in the phosphorus elimination in the feces independent of the In- 

 gestion, suggesting that all the forms of phosphorus were digested, 

 with liberation of phosphates; also that the fixed phosphorus of the 

 feces was entirely due to the cellular matter from the mucosa and 

 the intestinal flora. The soluble organic phosphorus in the feces 

 was relatively slight in quantity, even in the periods when " phytin " 

 was fed in liberal amounts. The calcium phytate added to the 

 washed-bran ration was not utilized as economically as the " phytin " 

 of the whole bran, and the "phytin" of the partially washed bran 

 also gave a lower digestion coefficient. 



The addition of "phytin" to the "low phosphorus" ration in- 

 creased the potassium Output in both feces and urine. The fecal 

 potassium dropped in quantity when the "phytin" was withheld, 

 but the urinary potassium did not. The amount of fecal mag- 

 nesium was constant through the several periods except in the 

 fourth, when it seems to have been influenced by the increased in- 

 take of calcium phytate. At the beginning of the experiment the 

 magnesium in the urine was equal to half that in the feces, but con- 

 tinually decreased until the mobile magnesium of the body had been 

 largely eliminated. The calcium in the urine increased remarkably 

 when the phosphorus intake decreased. In the calcium phytate 

 period, the calcium increase in the feces was approximately equiva- 

 lent to the calcium increase in the rations. 



In all cases the addition of organic phosphorus to the " low phos- 

 phorus " ration was followed by a decrease in the milk flow, and the 

 withdrawal of this phosphorus from the ration was followed by a 



