72 • .MAINE -TATE COLLEGE 



It appears that in the first two feeding periods fourteen 

 pounds of barley hay and mixed grain were fed besides the silage, 

 and that in the third period twelve pounds of Timothy hay took the 

 place of the barley hay. Forty pounds of Southern corn silage 

 were fed in the first and last periods and thirty pounds of Field 

 corn silage in the middle or second period. The daily digestible 

 food for each of the three periods was 14.23 pounds, 16 pounds 

 and 14 pounds respectively, so that the substitu ion of thirty pounds 

 of Maine field corn silage for forty pouuds of Southern corn silage 

 had the effect of increasing the daily composition of digestible mate- 

 rial by nearly two pounds. The fact that the daily ration of digest- 

 ible material did rot remain practically the same in all periods, 

 introduces an element of uncertainty into the conclusions which 

 may be drawn. 



The relative effect cf these rations mast be seen, if at all. by 

 studying their effect upon the bodily condition of the animals and 

 upon the production of milk. If we do this we find that the 

 cows lost from fifteen to thirty pounds weight in passing: from the 

 first to the second periods and that this loss was partially regained 

 daring the third period- These changes in live weight can be 

 readily explained by the less weight of silage eaten in the second 

 period, with no marked change in the quantity of water drank in any 

 p:riod. 



Ordinarily in an experiment of this kind, extending through three 

 months or more, there is a gradual but continuous decrease in the 

 volume of the milk yield, unless there is a change in the food favor- 

 able to an increased milk production. When we see that in the 

 second period of this experiment practically the same weight of 

 milk was produced, aud that owing to an increase in the dry matter 

 of the milk there was actually a larger production of milk solids, 

 we have good presumptive evidence that the ration containing the 

 thirty pounds of Field corn silage was more efficient than the pre- 

 vious ration containing forty pounds of Southern corn silage. This 

 evidence is strengthened by the fact that when in the third period a 

 return is made to the Southern corn silage the yield of milk solids 

 is decidedly diminished. Nevertheless, as stated in the preliminary 

 discussion of feeding experiments, minor differences in two rations. 

 such as existed in this experiment are not easily measured where so 

 many uncontrolled and unmeasured factors exist. 



