168 STORRS AGRICULTURAL EXPERIMENT STATION. 
protein only when the cow was yielding 22 pounds of milk. 
The German standards have been generally accepted in this 
country since their introduction in 1874. 
Some authorities have, however, advocated less amounts of 
protein, and some experiments would seem to show that the 
smaller amounts may sustain milk production equally as wellas 
the amount proposed in the German standards. Woll deduces 
from the reports of one hundred and twenty-eight dairymen 
what he calls the American ration for dairy cows. In this 
standard 2.15 pounds of protein, or 0.35 less than the German 
standard, is advocated. Heacker of Minnesota maintains that 
rations made up of home-grown grains and furnishing 2 pounds 
of protein, or even less, will sustain milk production equally 
as well as do the nitrogenous feeding stuffs containing larger 
amounts of protein. 
The feeding experiments of this Station, now under discus- 
sion, have heretofore been interpreted as indicating that the 
addition of protein to a ration not only sustains but stimulates 
milk production. 
In Table 80 the rations are averaged to show the effect on milk 
flow of the addition of protein to the ration. 
Upper division of the table.—Seven original rations fed to 
eighty-seven cows are compared with the recommended rations 
fed four weeks later. The protein in the original rations was in 
each case below 1.50 pounds; it averaged 1.40 pounds, and was 
increased to 2.09 pounds of protein in the recommended rations; 
the milk flow increased 0.83 pound following the change. It 
seems reasonable to assume, however, that a part of this in- 
creased milk flow was due to an increase of calories, which were 
below the standard, and to an increase of 1.37 pounds of grain 
in the ration. 
Middle division, Table 80.—Seven herds of ninety-six cows 
received a large addition of protein in the recommended ration, 
although the amount fed in the original ration averaged as high 
as the recommended ration scheduled in the upper division; yet 
there was a falling off of 0.14 pound in milk flow. 
Lower division, Table 80.—Seven herds of ninety-four cows 
received 0.17 pound more protein in the recommended than in the 
original rations, yet the increased milk flow is greater than in 
the middle division, where the increase in the protein was four 
times as great. 




