New York Agricultural Experiment Station. 545 



It appears that in Ration No. 1, 64 per cent, and in Eation No. 

 2, 42 per cent of the digested '' carbohydrates " consisted of 

 starch and sugar. 



Of the nitrogen-free extract not starch and sugar. 37 per cent 

 and 42 per cent were digested in the two cases, the amount being 

 nearly twice as much in Ration No. 2 as in No. 1. In Ration 

 No. 1, 20.7 per cent and in Ration No. 2, 80.2 per cent of the 

 digestible carbohydrates came from the fiber. From a theo- 

 retical point of view, when we consider that the pentose sugars 

 formed maybe less assimilable than the hexose,and that cellulose 

 digestion may in part be due to destructive fermentations, it is 

 reasonable to admit the possibility of unlike nutritive values for 

 a unit of digestible material from these two sources; but the 

 demonstration of this fact, if it be a fact, is a difficult matter. 

 and must be secured through some kind of experiments with 

 animals. A large difference in the value of twr rations may be 

 shown, perhaps, by ordinary feeding trials, but small differences 

 may be obscured by the errors to which such experiments are 

 subjected. The experiment subsequently described should not 

 be regarded, therefore, as furnishing evidence of the highest 

 character. This experiment was planned because of a desire to 

 learn whether the milk-producing capacity of a ration is modified 

 by the sources of the digestible compounds, other conditions be- 

 ing uniform. 



The Experiment. 



Rations similar to Nos. 1 and 2 in the kinds and proportions of 

 fodders and grains were used in an experiment with ten cow'S 

 selected from the Station herd. Some of the animals were in the 

 early stages of lactation, and none of them were so far advanced 

 as to endanger the reliability of the data. 



They were not all fed the same quantity of food, but the weight 

 of the ration varied with the appetite, size and production of tb/~ 

 several cows, 



35 



