460 Journal of Agricultural Research voiiii. no. 6 



the ingesta, especially the water, being eliminated only gradually during 

 the succeeding 12 hours and in part during the periods of lying as well 

 as of standing. It does not seem probable, therefore, that the heat pro- 

 duced in the mastication of the feed was an important factor in causing 

 the differences between the heat elimination of the animals when standing 

 or lying which were observed in these experiments. 



Another plausible suggestion seems to be a tendency of the animals 

 to greater restlessness and muscular activity in the standing position 

 when consuming the heavier rations. We are not able to submit direct 

 records to prove this, but indirect evidence is afforded by the fact that 

 the animals as a rule (31 cases out of 40) changed from the lying to the 

 standing position, and vice versa, more frequently on the heavier rations. 

 No such distinct effect was noticeable on the percentage of time spent 

 standing, it being greater in 22 cases and less m 19 on the heavier as 

 compared with the lighter rations and showing a considerable degree of 

 constancy in the individual animal. 



INDIVIDUAL DIFFERENCES 



In those cases where comparisons between different animals are possible 

 the average results, especially those obtained by comparing the maximum 

 and minimum rations, seem to indicate the existence of distinct individual 

 differences between different animals in this respect. 



The most noticeable case of this sort is that of animals A and B, in 

 experiments 190, 200, and 207, steer A being a typical beef animal, 

 while B, although of mixed blood (scrub), was quite distinctly of the 

 dairy type and of a more nervous temperament. In five cases out of six 

 the heat increment due to standing was greater with steer B than with 

 steer A, the average of all the results being 39 per cent higher for the 

 former, as the following summary shows: 



Ht'at increifienis in Calorics per kilogram of dry matter due to standing 



Feed. Steer A. Steer B. 



f-88 148 



Timothy hay I 442 346 



I 364 628 

 Timothy hay and wheat bran 168 200 



Timothy hay and grain mixture No. i l ,°° „'Jq 



Average 335 465 



A similar instance is afforded in experiments 208 and 209 by the ani- 

 mals C, E, and F. Steer C had received almost from birth as heavy feed- 

 ing as practicable, while E and F had received the same feeds in quantities 

 sufficient to insure normal growth but not to cause any material fattening. 

 The heat increments per kilogram of dry matter of feed were as follows : 



