A STUDY OF RATIONS FED TO MILCH COWS, 39 
DAIRY HERD L.—TESTS 43 AND 45. 
The tests made on this herd were carried out during Febru- 
ary and March, with the usual interval between the tests. 
There were nine cows in each test—five grade Jerseys, three 
natives, and a grade Holstein. The average estimated weight 
of the cows was 775 pounds. The average age was eight 
years. 
At the beginning of the first test the average time since pro- 
ducing the last calf was 3% months. ‘The ration fed in the 
first test was a narrow one and fully up to the standard here- 
tofore recommended by this Station for cows of the average 
weight of those in this herd. As the milk yields of different 
cows differed widely, it was thought advisable in the second 
test to compound a ration which should be regulated by the 
milk flow. For this purpose two mixtures were prepared. 
No. 1 was to be fed to all cows of the herd alike, while No. 2 
was to be fed in larger or smaller quantities in accordance with 
the milk flow. Mixture No. 2 was composed of concentrated 
nitrogenous by-products, and was intended to increase the pro- 
tein quite rapidly for the heavier milk producers. All cows 
giving from 10 to 20 pounds of milk per day were fed mixture 
No. 1 (see table), and in addition two pounds of mixture No. 2. 
Cows giving from 20 to 26 pounds had mixture No. 1 and three 
pounds of mixture No. 2 in addition, while cows giving from 
26 to 32 pounds had No. 1 and four pounds of No.2. It will be 
seen from the average ration given below that the second ration 
was an exceptionally heavy one in protein. It will also be 
noticed by reference to the formulas for feeding in accordance 
with the milk flow given in the following article, that the herd 
had larger quantities of protein than are there recommended 
for cows with a corresponding milk flow. Notwithstanding 
the heavy protein ration fed, the average milk flow for the 
nine cows in the second test was 1.3 pounds per day greater 
than in the first test, while the cost of the second ration was 
six-tenths of a cent more per day. (See table 10.) This 
farmer was producing milk for the Boston market, and at the 
average price (three cents per quart) the increase in milk flow 
in the case of the second ration more than covered the addi- 
tional cost. For most of the cows, however, the increase was 
very slight, and we are inclined to doubt if the feeding of as 
