94 Report or DEPARTMENT OF ANIMAL HusBANDRY OF THE 
was diminished from 77 grams daily to 16 grams, there is shown 
a small but unmistakable lowering of the percentage of fat. In 
this period from April 30 to May 17, when a similar reduction 
was made in the ingested phosphorus, the effect upon the fat 
percentage is much more marked, amounting to from six to seven- 
tenths per ct. During the lowering of the quantity of phosphorus 
fed the decrease in the fat content of the milk was a progressive 
one. In this period there did not appear to be a tendency, as was 
observed in Experiment 1, towards the restoration of the fat con- 
tent to its original proportions. The decrease in the percentage 
of milk solids is almost entirely accounted for by the decrease in 
the proportion of fat. (See Tables 27, 30-36.) 
6. Influence of the two rations upon production—During this 
experiment the yield of total milk solids and of casein gradually 
diminished without any apparent relation between production and 
the character of the rations. The yield of milk fat was percepti- 
bly lessened during the low phytin periods. (See Table 36.) 
7. Oestrum period.—This animal did not show the marked dis- 
turbance in this direction that was observed with cow 1. On the 
2oth of February, during the time she was passing from a low 
phytin ration to the one rich in that compound, the oestrum failed 
to appear. This was the only instance of the kind recorded with 
this animal. It was thought that perhaps a withdrawal of phytin 
from the ration for a long time would produce a result similar to 
that which occurred with cow 1, but during a thirty-day period of 
low phosphorus feeding, and afterwards, the oestrum regularly oc- 
curred. The animal afterwards became pregnant. 
GENERAL DISCUSSION OF THE THREE EXPERIMENTS. 
The data obtained from these three experiments involving the 
use of two animals, consistently support the following conclusions. 
Certain of the facts observed, which, with others, are here briefly 
summarized, agree with observations made by other investigators. 
1. The amount of outgoing phosphorus rose and fell with the 
quantity supplied in the food, though within narrower limits. When 
the phosphorus supply was abundant there was a storage of this 
element in the bodies of the animals, but during prolonged periods 
in which the supply of phosphorus was deficient there was with- 
drawn from the body store about 10 grams daily in several periods. 
