tal 
A STUDY OF RATIONS FED TO MILCH COWS. 61 
according to the amounts of protein in the rations fed. (See 
table, page 60.) The group composed of those herds receiving 
two pounds or less of digestible protein per cow per day pro- 
duced on the average 16.3 pounds of milk and .87 pounds of 
butter per day, while the group receiving more than two pounds 
of digestible protein per cow per day averaged 18.7 pounds of 
milk and 1.05 pounds of butter. This means that the herds 
which were fed the larger quantities of protein produced on 
the average 15 per cent. more milk and 20 per cent. more but- 
ter per cow than those fed the smaller quantities of protein. 
Consideration must be given to the fact that these are not 
comparative tests of the same lot of cows with different rations. 
It is, however, a striking illustration of results obtained in 
actual practice with rations varying quite widely in the amount 
of protein. The two groups of tests contained the same num- 
ber of herds (sixteen), and practically the same number of 
cows (one group had 227 and the other 226). While the 
breeds and general quality* of the two groups have not been 
compared closely, yet the statistics taken show that a large 
majority of the cows of both groups were of the same general 
class, that is, they were mainly Jerseys and Guernseys and 
their grades. 
It is impracticable to compare accurately the costs of the 
rations fed throughout these 32 tests, but the general results of 
our experiments indicate that the rations with relatively large 
proportions of protein are cheaper than those containing rela- 
tively smaller quantities.* In the 13 studies of two tests each 
on the same herds, the average cost of the rations high in pro- 
tein was one cent per day less than those lower in protein. In 
the 16 herds fed more than two pounds of digestible protein per 
cow per day the average increase of .18 pounds in the daily but- 
ter yield has a value, at 20 cents per pound, of 3.6 cents. It 
would not be fair to claim that this increase is due wholly to 
the better class of rations fed, but there is evidence that the 
rations used had considerable to do with the final results. 
THE EFFECT OF NARROW AND WIDE RATIONS ON MILK AND 
BUTTER YIELD. 
During the past four winters thirteen of the dairy herds 
studied were fed in the first test a ration made up by the 

* See reference to this in the following article. 
