274 



Journal of Agricultural Research 



Vol. XV, No. s 



GAINS BY BODY 



From the data of the Appendix the gains of protein, fat, and water by 

 the animal can be computed in the usual way with the results there 

 recorded in Table 6. In this computation the amount of water produced 

 by the oxidation of organic hydrogen has been disregarded. The results 

 are used only as a correction in the manner described on page 277, and it 

 may be shown that a disregard of the organic hydrogen introduces no 

 material error. Table VIII contains a summary of the gains of protein 

 and fat by periods. 



Table VIII.- — Average daily gains of protein and fat 



Feed and period. 



ALFALFA HAY. 



Period 5 



Period 6 ' 



Period 7 



ALFALFA HAY AND STARCH 



Period I 



Period 3 



Period 2 



Period 4 



METHANE FERMENTATION 



The extent of the methane fermentation per kilogram of dry matter 

 of the feed and per 100 gm. of digested carbohydrates is shown in Table 

 IX. In the hay the carbohydrates are the sum of the digested crude 

 fiber and nitrogen-free extract, while in the case of starch the compari- 

 son is made with the digested nitrogen-free extract. The minute 

 amount of crude fiber contained in the starch, as already noted, showed 

 an apparent negative digestibility. 



The extent to which the carbohydrates of the hay were subject to the 

 methane fermentation was substantially the same as the average of 

 17 previous determinations on alfalfa* — viz, 4.9 gm. of CH4 per 100 

 gm. of carbohydrates as compared with an average of 4.8. With the 

 mixed ration of hay and starch the fermentation showed a distinct 

 increase as the amount of feed was diminished. When, as in the latter 

 part of the table, this increase is computed upon the starch alone, assum- 

 ing average figures for the hay, it becomes, of course, relatively more 

 marked and considerably exceeds Kellner's average of 3.07.^ The 

 relative extent of the fermentation was apparently abnormally great 

 in period 3 which, as already noted, also gave apparently exceptional 

 results as regards digestibility. The means, omitting period 3, have 

 therefore been included in the table. 



• Armsby, H. p., and Fries, J. A. net energy VAtuEs op feeding stuffs for cattle. In Jour. 

 Agr. Research, v. 3, no. 6, p. 450. 1915. 

 ' Kellner, 0., and Kohler, A. untersuchungen uber den stoff- und energie-umsatz des 



ERWACHSENEN RINDBS BEI ERHALTUNGS- UND PRODUKTIONSFUTTER. Jn Landw. Vers. Stat., Bd. 52, p. 



423, 1900. 



