224 Repoet of Farmers' Institutes 



OT to. work out some other method that might be more nearly 

 accurate, I wish to present a few tables for comparison. Before 

 doing this, however, I wish to give credit to Prof. J. M. Bartlett 

 or Orono, Maine for the data on " Digestion Experiments with 

 Poultry " as found in Bulletin jSTo. 184 of that station, and also 

 to acknowledge free use of the appendix tables in Prof. W. A. 

 Henry's handbook on '' Feeds and Feeding " where the coeffi- 

 cients of digestion for cattle and swine were obtained. 



It might be well to state here the apparent accuracy of the 

 methods used, and the apparent reliability of results obtained in 

 experiments to determine the digestibility of feeds by poultry. 

 The method of separating the feces from the urine by a surgical 

 operation to make separate exits for the large intestine and the 

 renal system, has been in use for some time, but for the most part 

 has proved unsuccessful. It is an artificial condition, and as such 

 undonibtedly has considerable influence on the health and activity 

 of the bird, as well as on the physiological processes of digestion, 

 absorbtion and excretion. The method used at Orono, Me., on 

 which most of the data in this paper are based, was secured by 

 collecting the feces and urine together as normally discharged, 

 and then making chemical analysis to determine the amount of 

 uric acid. This, as representing the urine, was then subtracted 

 from the total, and the balance taken as the feces. By actual test 

 as high as 98 per cent accuracy was secured in these detenni- 

 nations and it would seem that the data thus obtained are quite 

 reliable. At least, it is the best we have and can undoubtedly be 

 used with considerable safety for the purpose of comparison with 

 similar factors for other animals. 



In Table l^o. 1 are compared the percentages of the nutrients in 

 several feeds that are digested respectively by poultry, swine and 

 cattle. Unfortunately, we cannot compare these figures for the 

 entire sixteen feeds which I am able to find as having been used 

 in poultry digestion experiments, for only eight feeds are common 

 to each of the three groups of animals, and one of these, 

 potatoes, is not ordinarily considered as being of great value 

 from a nutritive standpoint. 



We are limited, therefore, to the comparison of only seven 

 feeds. Of these I wish particularly to call attention to the one 



