THE FUNCTION OF GRIT IN THE GIZZARD OF 
THE FOWL 1 
By B. F. Kaupp 
Poultry Investigator and Pathologist , North Carolina Agricultural Experiment Station 
INTRODUCTION 
As a preliminary step in the study of the nutrition of fowls, it is neces¬ 
sary to determine the function of grit in the gizzard and the length of 
time that it will remain there and serve a useful purpose. A review of 
the literature of the subject discloses no record of experiments made to 
discover these facts. 
THE PROBLEM 
It is a matter of common knowledge that, since the fowl has no teeth 
with which to grind its food, the muscular walls of the gizzard contract 
upon its contents and reduce the food to fineness. The object of this 
investigation was to discover how long such grit is useful in the gizzard, 
how often it must be replenished, whether a hen constantly consumes 
more grit than she requires, and if so, whether the surplus is kept in the 
gizzard. 
EXPERIMENTAL METHODS 
Barred Plymouth Rock hens 2 or 3 years old were used in the experi¬ 
ment. They were kept in coops 18 inches square. The coops were 
provided with i-inch mesh wire bottoms so that the excreta would pass 
through to a second floor as soon as voided. A possible reconsumption 
of any grit passed in the excreta was thus prevented. Hens were killed 
at different periods and the gizzard content examined for the grit which 
still remained. 
Analyses of the intake and outgo of the feed and the weight of the 
birds were made to determine whether or not the grit content of the 
gizzard was sufficient for the normal physiological processes of that 
organ. 
The feed for 365 days, the duration of the test, consisted of the regular 
scratch feed and dry mash used at the Station plant. The following 
tabulation offers a comparative study of the amount of grit contained in 
the gizzards of hens killed at different intervals of time. This information 
is differently presented in Plate 1. 
1 Accepted for publication Nov. i, 1923. 
Vol. XXVII, No. 6 
Feb. 9, 1924 
Key No. N. C.—16 
Journal of Agricultural Research, 
Washington, D. C. 
(413) 
