UTAH ACADEMY OF SCIENCES 137 
EFFECT OF THE AMOUNT OF PROTEIN CONSUMED 
UPON DIGESTION AND METABOLISM IN LAMBS 
AND UPON THE COMPOSITION OF THEIR 
FLESH AND BLOOD. 
By W. E. CARROLL. 
(Conclusions only). 
While the data presented seem to warrant the follow- 
ing conclusions, it should be borne in mind that the differ- 
ences in protein consumption between animals of the three 
lots were not great, and that even the low protein animals 
probably received protein somewhat in excess of their truly 
minimum requirements. 
1. The amount and the chemical composition of the 
feces of lambs is independent of the amount of protein 
consumed. This is true whether the corrected or the un- 
corrected data are considered. 
2. The feces of lambs contain considerable quantities 
of purely metabolic products. To determine accurately the 
extent of digestion of feeds, the only correction usually 
made—that for metabolic protein—is in itself insufficient. 
“Metabolic ash,” and no doubt other substances as well, in- 
fluence the accuracy of the coefficients of digestion. 
8. The coefficients which are especially affected are 
those of protein, fat, and ash. On account of the methods 
used, little confidence can be placed in those of fat and ash 
as ordinarily reported. The correction for metabolic pro- 
tein, while the method is far from satisfactory, should al- 
ways be made. 
4. The amount of metabolic protein in the feces is not 
influenced by the protein intake. It is more nearly related 
to the total dry matter consumed than to the amount of dry 
matter digested as reported by some investigators. 
5. The amount of protein consumed (the rations being 
similar in other respects) does not influence the extent to 
which any of the food nutrients are digested when judged 
by corrected coefficients of digestion. 
