June i, 1921 
Some Fundamentals of Stable Ventilation 
357 
To illustrate the method of computing the heat increment due to the 
consumption of feed, that caused by a pound of oats is calculated as 
follows, the digestible nutrients being those given in Bulletin 186 of the 
Kansas Experiment Station (15), with the exception of those for clover 
hay, which are taken from Henry and Morrison’s tables (ro), from 
which have also been obtained the data for total crude fiber. 
Digestible nutrients of oats 
Protein. 0.107 pound. 
Carbohydrates. 0.503 pound. 
Fat (3.8X2.4). 0.092 pound. 
Total. 0.702 pound. 
Total crude fiber. 0.109 pound. 
Metabolizable energy.1,796 caloriesXo.702 = 1,260.8 calories. 
Heat increment 
9 per cent metabolizable energy. 1,260.8X0.09 =113.5 calories. 
Additional for crude fiber. 1,202 Xo.io9=i3i.o calories. 
Total heat increment.244.5 calories. 
The heat increment caused by other feeding stuffs has been computed 
in a similar manner. 
FASTING KATABOUSM 
The total heat production of the horse was estimated by Zuntz and 
Hagemann ( 18 ) from the respiratory exchange determined by means of 
a respiration apparatus for short periods after the consumption of differ¬ 
ent rations. From a comparison of the results and by the indirect method 
of computing the heat increment due to the work of digestion which has 
been illustrated they have computed the average fasting katabolism of 
the horse to be 4,100 calories per 1,000 pounds live weight. In propor¬ 
tion to the two-thirds power of the live weight the fasting katabolism 
of horses, as computed by Armsby, is given in Table IX. 
Tabus IX .—Fasting katabolism of horses 
Live weight. 
Fasting katab¬ 
olism per 
head. 
I,ive weight. 
Fasting katab¬ 
olism per 
head. 
Calories . 
Calories. 
150 
1,160 
1,000 
4, IOO 
250 
1,630 
1,250 
4,760 
500 
2,580 
1 , 5°° 
5.370 
750 
3.390 
TYPICAL WEIGHTS AND RATIONS OF HORSES 
As examples of typical live weights and rations for horses upon which 
to base the computation of the heat production of these animals the 
following, suggested, at the request of Mr. Clarkson, by J. L. Edmonds, 
of the Illinois College of Agriculture, have been used. 
