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: 
i d Pro- Meta- pi 
YekieperDay | bolizable | Average|Gain or Loss| xutritive 
a ra fe epee Weight, | by Body, fous 
Pina. ' Cals, ¢ Kes. Grms. oa 
Experiment I. 
Steer 1.......... 129 7956 420 —2.51 20.1 
a ee eae eee 113 7588 450 —0.39 20.4 
HO Bik a daces. sare 133 7191 400 —1.08 18.6 
Experiment II: 
Steer 1.......... 192 8144 420 +1.76 13.4 
EDs eae wes 202 9590 450 +4,23 13.6 
SBM i ocak aay 209 8084 400 +4.62 12.8 
Experiment VI: 
teer 1...... 0... 297 11130 450 +4.67 10.9 
We De as Biv caitars 277 11318 490 +6.47 10.9 
BEY ZB Akane a eiatets 314 11324 430 +2.65 10.6 
Experiment VII: 
teer 1...... 2... 156 11955 450 "| +5.68 23.0 
OO Ds elt a ei tvel Sp 131 11904 490 +3.98 25.3 
BN Bie. sce Srtvaae oe 152 11557 430 +4.15 23.9 
Experiment VIII: 
beer Li cess. nee 258 11634 543 +0.26 10.4 
ae Perera 242 12976 629 —0.20 10.7 
ers eC ee eee 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. 
Digitized by Microsoft® 
