FUNCTIONS OF THE NUTRIENTS 171 



250. Influence of size of ration on losses of methane. — 

 The losses through gas evolution were found to be greater 

 in twenty-nine cases out of thirty-one with the lighter 

 ration and tended to be somewhat greater on the mixed 

 ration with a very much larger proportion of readily 

 soluble carbohydrates. This simply means that the 

 "bacterial fermentation of the carbohydrates in the di- 

 gestive tract of cattle proceeds to a distinctly greater 

 extent on light than on heavy rations." 



251. Influence of size of ration on losses in the un- 

 digested residue. — ^As is well known, this loss will be by 

 no means uniform as this residue is proportionately much 

 larger with coarse foods than with grain foods. In these 

 comparisons there seemed to be practically no difference in 

 the proportion of loss as between heavy and light rations, 

 these results not agreeing with former observations. 



252. Influence of individuality on energy losses. — 

 Comparison was made between a pure-bred Shorthorn 

 steer and a so-called scrub. Practically no difference in 

 the loss of chemical energy was discovered as between 

 these two animals. 



253. Estimates of metabolizabl6 energy on the basis 

 of digestible organic matter. — It is discovered that the 

 metabolizable energy in a unit of digestible organic 

 matter is fairly uniform as between the different coarse 

 fodders on the one hand and the various concentrates 

 on the other. Various investigators have studied this 

 question and their results show a satisfactory agreement. 

 It appears that the metabolizable energy which may be 

 derived from the several feeding-stuffs will vary quite 

 directly with the proportion of digestible dry matter. 

 The following table shows the figures reached by several 

 investigators: 



