207 



How much of the observed increase or decrease in live weight is act- 

 ually gain or loss in flesh and how much is due to changes in the weight 

 of contents of the alimentary canal or to bodily disturbances caused by 

 change in diet, it is impossible to say. According to the detailed tabular 

 statement of the amounts of water drunk and in the food from February 

 17 to March 2, the heifers fed silage had in all about 7 pounds more 

 water daily than those fed corn fodder. 



Taking the whole experiment into account, the total gain in live 

 weight of the two lots as shown by the scales was practically the same ; 

 but the heifers fed corn fodder required for every 100 pounds of in- 

 crease 759 pounds of water-free substance ; and the heifers which 

 were fed silage during the first two periods and corn fodder the third 

 period required 817 pounds of water-free substance for every 100 i)ounds 

 of increase. Thus the heifers fed silage during the first two i^eriods and 

 corn fodder the third required more dry matter to make a pound of in- 

 crease than those fed corn fodder the whole time. In brief, as indi- 

 cated by the scales, the gain in weight per pound of dry matter of feed 

 was in favor of the silage in the first period and of corn fodder in the 

 second; so that at the end of the second period, the results with the two 

 were about equal. In the third period, however, when the silage-fed 

 lot changed to corn fodder, the difference was decidedly in favor of the 

 corn -fodder-fed lot. 



For this apparent superiority of the corn fodder three possible ex- 

 planations are suggested by the author. (1) As shown by analyses by 

 Mr. Farrington (see beyond), the character of the protein in the corn 

 had been changed in ensiling, so that the albuminoid protein had been 

 reduced 33 per cent in the silage. (2) "About 7 pounds more water 

 were consumed daily by each heifer fed silage than those fed corn fod- 

 der." The elimination of this by the excretory organs, including the 

 skin (evaporation), may have been done at the expense of the energy of 

 the food. (3) It may be that, as suggested by Weiske, the silage passes 

 more rapidly through the bowels and is less completely digested. " The 

 relative digestibility of the field-cured and silage fodders, however, is 

 still unsettled." 



[It will be recalled that for the sixty-three days of the first two 

 periods when silage was actually compared with corn fodder the fodder- 

 fed lot gained 472 and the silage-fed lot 511 pounds, while the gain per 

 pound of dry matter of food was practically the same; that is to say, 

 the silage-fed animals ate more dry matter and gained proportionally in 

 weight. But in the third period of twenty-one days the lot accustomed 

 to corn fodder gained 93 ])Ounds, while the lot changed from silage to 

 fodder gained only 40 pounds. Whether and how far this apparent ad- 

 vantage in favor of the corn fodder was due to the inferior effect of 

 silage, or to change of diet, or to differences in weight of contents of the 

 alimentary canal which may occur even with the same diet, it is scarcely 

 possible to say. J 



