142 PRINCIPLES OF ANIMAL NUTRITION. 
Experiments by the writer * have shown that nitrogen equi- 
librium may be maintained, for a time at least, on even smaller 
amounts of protein than the above figures would indicate. The 
figures in the first column of the following table signify the proteid 
nitrogen only of the food multiplied by 6.25: 
Digested Pro- Meta- i 
tails per Day polizable pmeee Caney oes Nutritive 
and 500 Kgs. Energy Weight,| by Body, Ratio 
a bal t, tga Kgs. Grms. Abts 
Experiment I: 
teer 1 129 7956 420 —2.51 20.1 
oo? 113 7588 450 —0.39 20.4 
“ 3 133 7191 400 —1.08 18.6 
Experiment II; 
OCT sas atch tein ve 192 8144 420 +1.76 13.4 
BE SD aasecacece Desi 202 9590 450 +4.23 13.6 
he wilaatatects eats 209 8084 400 +4.62 12.8 
Experiment VI: 
Heer Vics nas spew a 297 11130 450 +4.67 10.9 
ae errr 277 11318 490 +6.47 10.9 
OO Biv d eee aw 314 11324 430 +2.65 10.6 
Experiment VII 
teer 1........., 156 11955 450 +5.68 23.0 
a ere 131 11904 490 +3.98 25.3 
Pe SD Nin gee Sasa 152 11557 430 +4.15 23.9 
Experiment VIII: 
Heer. sas staid 258 11634 543 +0.26 10.4 
pala? een serene 242 12976 629 —0.20 10.7 
SED TB eats Bare ior 275 12030 516 |) —2.31 10.6 
While the above data are hardly sufficient to fix absolutely the 
minimum of proteids for cattle on a maintenance ration, they indi- 
cate clearly that from 200 to 300 grams of digestible protein per day 
.is at least sufficient for a steer weighing 500 kgs., and there is a 
“ possibility that the amount may be somewhat further reduced. 
Although we are unable to compare this with the fasting meta- 
bolism, a comparison on the basis of live weight with some of the 
results previously cited shows that the minimum demand for pro- 
teids on the part of cattle is relatively much less than on the part 
of carnivora. Thus the results obtained by Lehmann et. al. and 
Munk (p. 137), and by Voit & Korkunoff (p. 138), computed in 
* Penna. Expt. Station, Bull. 42, 165. 
