10 .BULLETIN 459, U. S. DEPARTMENT OF AGRICULTURE. 



comparing feeding stuffs on the basis of the digestible matter which 

 they contain is seriously erroneous and to permit the computation of 

 at least tentative net energy values. A summary of the results of 

 these investigations has been published in Bulletin 142 of the Penn- 

 sylvania Experiment Station together with an outline of the methods 

 used for computing the net energy values of feeding stuffs which 

 have not been the subject of direct experiment. 



Henry and Morrison 1 have recently published a very valuable com- 

 pilation of American analyses of feeding stuffs and of the results 

 of American digestion experiments, and on this basis have calcu- 

 lated the content of digestible nutrients (for ruminants) in a great 

 variety of feeding stuffs. 



With the permission of these authors, the writer, in cooperation 

 with Prof. F. S. Putney, of The Pennsylvania State College, has com- 

 puted from their tables the net energy values of the more important 

 feeding stuffs with the results contained in the following table, 

 which includes the digestible (true) protein and also the nonprotein 

 estimated on the basis of Kellner's averages. In regard to this 

 table it is to be remarked — 



First. Both the digestion coefficients used by Henry and Morrison 

 and the data for the expenditure of energy due to feed consumption 

 are derived exclusively from experiments on ruminants (cattle). 

 Consequently, the net energy values here computed are directly 

 applicable to ruminants only. 



Second. The table shows primarily the net energy values for main- 

 tenance or fattening. There seems good reason for believing, how- 

 ever, that they may be taken without serious error to represent 

 also the net energy values for growth and at least the relative values 

 for milk production. Kellner believes that the same net energy 

 values may also be regarded as expressing with sufficient accuracy 

 the relative values of feeding stuffs for horses and for swine. The 

 requirements for these animals, therefore, as tabulated on the follow- 

 ing pages, are substantially those given by Kellner. 



i Feeds and Feeding, 15th edition, pp. 638-666. 



