120 EXPERIMENT STATION. [Jan. 



Conclusions. 



The following general conclusions may be drawn from the 

 experiments reported : — 



1. A large excess of digestible protein (1.5 pounds, or 100 

 per cent.) above the protein minimum increased the flow of 

 milk some 15 per cent, in experiments extending over periods 

 of four weeks. 



2. No particular difference was noted in the milk yield in 

 case of two herds of cows receiving the same amount of total 

 digestible matter, one receiving 65 per cent, and the other 122 

 per cent, of digestible protein above the protein minimum. Such 

 a result indicates, at least, that the former excess was sufficient. 



3. A 50 per cent, excess of digestible protein daily above the 

 protein minimum in an experiment by the reversal method, 

 extending over a period of nine weeks, produced some 5.9 per 

 cent, more milk than did a ration with 21 per cent, excess 

 protein. 



4. Under similar conditions an excess, above the minimum, 

 of 05 per cent, digestible protein produced 7.4 per cent, more 

 milk than did an excess of 39 per cent, (experiment covered 

 twenty-six days ) . 



5. In experiment YL, extending over a period of eleven 

 weeks with twelve cows, by the group method, an excess of 

 .54 of a pound of protein, or 31.3 per cent., over the protein 

 minimum, produced an apparent increase of 10 per cent, in 

 the milk yield. 



In experiment VIIL, extending over periods of twenty-four 

 to thirty weeks with ten cows, by the group method, the cows 

 receiving the protein minimum did not shrink any more than 

 those receiving each .44 of a pound, or 28 per cent., protein 

 abo\'e the minimum. 



G. The group method of experimentation is best suited for 

 conducting experiments where a relatively large number of ani- 

 mals — twenty or more — is available. With a less number the 

 influence of individuality is altogether too pronounced. 



7. An excess of 30 per cent, of digestible crude protein above 

 the protein minimum (equal to 1.80 pounds of protein per 



