482 



Journal of Agricultural Research 



Vol. Ill, No. 6 



between the observed and the computed heat production in four out of 

 six periods, although it is true that this difference was not relatively 

 greater than in experiment 190. Whether these facts are in any degree 

 responsible for what seem abnormally low results and for the very large 

 proportion of the heat increment apparently due to stimulation of the 

 standing metabolism, it is hard to say, but the results differ so widely 

 from all the others that we feel justified in rejecting them, pending other 

 experiments, particularly since the total increment observed in experi- 

 ment 179 agrees very well with that computed on page 478 from Kellner's 

 experiments. Experiment 212 fails to show any significant difference 

 between alfalfa hay and alfalfa meal, and the two have been averaged 

 together. In the case of maize meal it is difficult to decide which, if 

 either, of the discordant results is worthy of most credit. The figure 

 of only 393 Calories per kilogram for the increase of the metabolism 

 of the animal when lying, however, seems so low that we are inclined 

 to attach greater weight to the later experiment. For grain mixture 

 No. 2 we have used the results computed from periods i and 2 in the 

 belief that the heat production in period 3 was rendered abnormally 

 high by the restlessness of the animals, owing to the small bulk of their 

 ration (compare p. 461), although the difference is scarcely significant. 



In the Mockern experiments Kellner's results on heavy rations of starch 

 appear to be abnonnal in that the methane production was not increased, 

 while much starch escaped digestion. Kiiim's results were obtained on 

 rations of coarse fodder and starch alone with a nutritive ratio of about 

 I : 20, or even wider — i. e., under conditions seldom or never realized in 

 practice. Kellner's average for medium rations, therefore, would 

 appear to correspond most nearly to normal conditions. The results on 

 peanut oil were irregular in several respects, but the rejection of the very 

 high result with ox D seems justified. Of the computed results of Kell- 

 ner's experiments, as given on page 478, those for the oil meals seem un- 

 questionably too low and have been rejected. 



On the foregoing assumptions we have formulated the following 

 averages for the total energy expenditure resulting from the consumption 

 of I kg. of the dry matter of the feeds named. It may not be superfluous 

 to call attention again to the fact that these figures are simply general 

 averages, derived in some instances from quite discordant single results, 

 and that, as both our own and the Mockern experiments show, they are 

 subject to very considerable variations in individual cases. 



Average energy expenditure per kilogram oj dry matter eaten 



COARSE FODDERS 



Calories. 



Timothy hay "^ 782 



Red clover hay 962 



Mixed hay 980 



Alfalfa hay i, 169 



"Grass hay" i, 045 



Rowen 958 



Meadow hay i, 254 



Maize stover i, 065 



Barley straw 877 



Oat straw i, 014 



Wheat straw i, 138 



Extracted straw i, 160 



Clover hay 932 



CONCENTRATES 



Calories. 



Maize meal i, 434 



Hominy chop 1.36S 



UTieat bran i, 177 



Grain mixture No. i i, 327 



Grain mixture No. 2 i, 141 



Beet molasses 988 



Starch 1,248 



Peanut oil i> 727 



Wieat gluten 2, 294 



