A STUDY OF THE METABOLISM AND PHYS. 
IOLOGICAL EFFECTS OF CERTAIN 
PHOSPHORUS COMPOUNDS 
WITH MILCH COWS.* 
WH. JORDAN, Ey BAHAR BAND VAP jerk ed LON 
INTRODUCTION. 
The metabolism and functions of the ash ingredients of cattle 
foods have received relatively little attention from scientific inves- 
tigators up to the present time. This is true even of so important 
an element as phosphorus. So far, investigators have given their 
attention chiefly to studies of the metabolism and functions of the 
compounds included in the three classes, proteids, carbohydrates 
and fats. There is every reason for believing, however, that some 
of the elements which appear in plant ash sustain just as important 
practical relations to animal production of various kinds as do 
nitrogen and carbon in their various combinations. 
The purpose of the investigations herein reported has been to 
study some of the nutritive relations and functions of the phos- 
phorus compounds of cattle foods. The results reached in the 
preliminary stages of this work have already been reported in bul- 
letins Nos. 238 and 250 in which certain conclusions as to the status 
of phosphorus in feeding stuffs are set forth. 
PARTIAL REVIEW OF PREVIOUS INVESTIGATIONS. 
In studies of phosphorus metabolism numerous experiments with 
small animals, as dogs, calves, lambs and pigs, have been carried 
on both in this country! and abroad?, either with the purpose of 
determining the relative therapeutic values of different calcium phos- 
phates in the pathological condition known as rickets, or their values 

* A reprint of Technical Bulletin No. 1. 
*Henry. Wis. Agrl. Expt. Sta. Ann. Rpt., 6:15. 1880. 
*N. Schenke. Landw. Vers. Stat., 58:19. 1903. 
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