785 
oct. 15,1925 Calcium Phosphate as Supplement to Dairy Ration 
being rightly placed and 58.6 per cent of the nonmineral group. All 
agreed that, with two or three exceptions, there was no significant 
difference in the general appearance and handling of the cows. 
Body Weight 
For obvious reasons, only those cows which were mature at the 
beginning of the experiment can be considered under this heading. 
There are seven such individuals in the herd, and an endeavor has 
been made to have the weight for each of these at the beginning of 
the experiment and during the present season as comparable as 
possible. This has been done by noting the stage of lactation and 
gestation of each cow when the experiment started and by fixing a 
date during this present year at which time she was in approximately 
the same stage of gestation and lactation. An average of four 
separate weighings, one each on the first and second days of two 
consecutive months, has been taken in each instance. (See Table IV.) 
Table IV. — Net gain or loss in weight of the aged cows 
At beginning of experiment 
Date this season 
when cow was at 
approximately 
the same stage of 
lactation and 
gestation 
Average 
weight 
at that 
time 
Cow No. 
Age in 
years 
Average 
weight 
in 
pounds 
Stage in 
lactation 
in 
months 
Stage in 
gestation 
in 
months 
Gain or 
loss 
Nonmineral group: 
8 
9 
1,215 
1,100 
910 
4 
(*) 
1 
June, 1924_:_ 
1,235 
1,085 
+20 
10. 
7 
3 
December, 1923. _. 
February, 1923 *>__ 
-15 
16..1..:_ 
8 
11 
6 
920 
+10 
19. 
5 
890 
2 
(*) 
December, 1923_ 
860 
-30 
Net gain or loss 
for tbe group. 
-15 
Mineral group: 
9. . 
7 
1,230 
' 1,210 
3 
1 
October, 1923. 
1,205 
-25 
11. 
7 
4 
1 
March, 1924. .. 
1,285 
+75 
17 
9 
870 
2 
(«) 
December, 1923_ 
850 
-20 
Net gain or loss 
for the group 
+30 
1 
• Not bred. 
h Can not get this cow with calf this year, so her weight a year ago is taken. 
Because of the considerable variation in weights of cows, even 
from day to day, such small differences as noted above -can not be 
considered of any significance. 
Milk Production 
As noted elsewhere in this paper, Meigs (22) is of the opinion 
that cows fed rations deficient in mineral matter react to the defi¬ 
ciency by a marked decrease in milk flow from year to year. 
The effect of the experiment in this respect has been noted by a 
careful study of the production records obtained by the writers. 
The results are presented in the accompanying charts, which show 
the-average daily milk yield per cow by months, for the whole herd 
since January, 1920, and for the two groups since the commence¬ 
ment of the experiment in December, 1921. 
It is quite evident (Chart I) that thus far the low-ash rations have 
had no appreciable effect on the milk yield of the herd as a whole. 
Also, it is equally evident (Charts II and III) that the mineral 
supplement has had no effect. The average daily milk yield of the 
cows in the mineral group has been slightly lower all through the 
