102. Report oF DEPARTMENT OF ANIMAL HUSBANDRY OF THE 
phosphorus supply affected in any way the constitution of the milk 
fat. In order to obtain evidence on this point the butter-fat was 
examined for five different periods in experiment 3. 
I. Fat from the milk of April 19th to 20th. High phosphorus 
feeding immediately after the change from a low phosphorus ration. 
2. Fat from milk of April 29 to 30, ten days after the change 
from a low phosphorus to a high phosphorus ration. 
3. Fat from milk of May 7 to 8. Low phosphorus ration imme- 
diately after a change from the high phosphorus ration. 
4. Fat from the milk of May 22 to 23, fifteen days after the 
change from a high phosphorus ration. 
5. Fat from milk six weeks after the cow had been placed on 
the regular ration of the Station herd. This represents butter fat 
produced under entirely normal conditions. 
The results of these examinations are given in the following 
table: 
TABLE XLIV.—ComposITION OF BUTTER FATS. 


| | 
No. Phosphorus Volatile Soluble Insoluble Iodine Kost No Melting 





ration. acids. acids. acids. absorp. point. 
Per ct. Per ct. Per. ct: Per ct. 
5 hee agi eee 31262 ee (anl 86.89 26.91 239 SL soo 
ree Mie we bed 01) Ae rca 33.82 5.60 85.99 26.47 240 30.70 
Dicks OW ome ae 29 60 4.91 87.40 25.41 236 32.44 
4.. Lowe Lite 26.29 4.75 feo! 26.23 234 Soule 
Bey Normals 2.1 Z6¥2i Del0 88.59 37.93 | 232 BLeoOO 

The indications are that the constitution of the milk fat was 
somewhat modified by the change in the rations. The volatile and 
soluble fatty acids are in smaller proportion in the fat produced 
by the low phasphorus ration while the melting point is somewhat 
higher, facts that are entirely consistent with each other, and are 
an additional indication of a specific influence upon milk-fat secre- 
tion of the compounds taken out of the bran by leaching with 
water. . 
The source of the phosphorus given up from the body store 
during the periods of low phosphorus feeding.—Since these two 
animals were able to sustain a loss of phosphorus compounds from 
the body store during considerable periods of time without any ap- 
parently serious consequences to the general health, it becomes an 
interesting question as to what part of the body store was drawn 
N 
