970 



EXPERIMENT STATION RECORD. 



;ul libitum (usually 5 lbs.) in addition. In deterniining the nutritive value of 

 the ration it was found that the composition of the ground feed agreed so 

 closely vi'ith the composition, as shown by analyses, of the separate ingredients 

 that it was evident the grain mixture could be considered as one food mate- 

 rial in making calculations and computations. 



The following table shows the average results of the 6 digestion trials as 

 determined and as calculated by means of digestion coefficients used with both 

 determined and average values for the composition of feeding stuffs : 



Comparison of (leterniined and calculated ainoinits of nutrients digested from 



same ration. 



" It will be observed there is a reasonably close agreement between the actual 

 digestible nutrients of this ration . . . and the calculated digestible nutrients. 

 These results show that for all practical purposes the tables of digestible nutri- 

 ents, as recorded in standard works on feeding compiled from the average com- 

 position of American feeding stuffs and average digestion cnetticients, are suffi- 

 ciently accurate for the general calculation of rations. The difference between 

 the actual and calculated nutrients, as found in this investigation, in wliich (! 

 steers of widely different types were used, was small, amounting in 1 day to 

 less than i 11>. of dry matter and less than ^ lb. per day of protein. 



" In the case of the individual steers the digestibility of the protein i-anged 

 from 59.82 to ()(>.()4 per cent and the carbohydrates from 7<;.()8 to 82.08 per cent. 

 It is to be noted that in a mixed ration, such as u.sed in this investigation, only 

 about two-thirds of the dry matter ... a little less than two-thirds of the pro- 

 tein, and about three-(iuarters of the fat and carbohydrates of the food consumed 

 were digested and utilized by the body. These results show that under the con- 

 dition of the- experiment in which a mixed ration was used from one-third to 

 one-fourth of the nutrients were voided as indigestible matter in the feces." 



In the author's opinion the results of the experiments emphasize the desira- 

 bility of using coarse fodder which supplies a maximum amount of protein. 



The energy value of the urine was determined to secure data for calculating 

 the available energy of the ration. The nitrogen in the urine and the balance 

 of income and outgo of this constituent were also determined. 



" In this investigation an avei'age of <>i.92 per cent of the total energy of the 

 ration measured in calories or heat units was available to the l)ody. In the 

 daily ration the food sup])lies 47,87.5 calories and 3O.(!O0 calories were available 

 to the body. While this is apparently a large loss, it is a more economical use 

 of the fuel value than a steam engine where only about 15 per cent of the energy 

 is available." 



