58 STORRS AGRICULTURAL EXPERIMENT STATION. 
The lower part of each table gives the kinds and amounts of 
the different feeding stuffs eaten per day, and the weights of the 
digestible nutrients (protein, fat and carbohydrates) which they 
were estimated to furnish. The weights of foods and nutrients 
are calculated per 1,000 pounds live weight and also ‘‘ per aver- 
age weight’’ of each herd. ‘These last figures, which are given 
in the last five columns of the table, represent the average 
amount actually fed per animal. 
All of the different feeding stuffs used in these rations 
were analyzed. From the weights of the different feeding 
stuffs, the results of the analyses, and the digestion coeff- 
cients given in the following table, the weights of digestible 
nutrients were calculated in the usual way. ‘The fuel value, or 
potential energy furnished by the different foods, was obtained 
‘by multiplying the number of pounds of protein and of carbo- 
hydrates by 1,860, and the number of pounds of fat by 4,220, 
and taking the sum of these three products as the number of 
calories of potential energy in the materials. 
The rations fed in 1895-96 are summarized with those of the 
three previous winters in table 5. 
DIGESTIBILITY OF FEEDING STUFEFS. 
We have had frequent occasion to insist in the publications 
of this Station that the estimates of the quantities of nutrients 
in these rations, and in feeding stuffs generally, are not 
absolutely accurate unless the feeding stuffs themselves are 
accurately analyzed, since materials of the same kind vary 
considerably in composition and the figures ordinarily printed 
in tables of composition represent only general averages. ‘The 
same is true of the digestibility of a given amount of protein 
in a feeding stuff or a ration, a larger or smaller portion may 
be digested in a given case. The proportion digested will 
depend upon the digestive powers of the animal and the char- 
acter of the feeding stuff. The same is true of the fats and 
carbohydrates. The proportions of each ingredient which are 
supposed to be actually digested are commonly expressed in 
percentages, and in that form are designated as coefficients of 
digestibility.* | 

* For explanations of these subjects, see articles on digestion experiments, and 
especially articles on the digestibility of feeding stuffs and the calculation of rations 
in the Report for 1893, pages 156 and 168. > 
