TIME REQUIRED FOR FOOD TO PASS THROUGH THE 
INTESTINAL TRACT OF FOWLS 1 
By B. F. Kaupp and J. E. Ivey, Laboratory of Poultry Investigations and Pathology , 
North Carolina Agricultural Experiment Station 
INTRODUCTION 
As a preliminary to our study of the digestive coefficients of poultry 
feeds we wished to run some tests to determine the length of time required 
for feed to pass the entire length of the digestive tract. The length of 
the small intestine in a hen of average size is about 61.7 inches, and that 
of the large intestine 4.61 inches, 2 making a total of 66.3 inches, which, 
added to the length of the second portion of the esophagus, the pro- 
ventriculous, and gizzard makes approximately 71.5 inches for the food 
to pass. 
THE PROBLEM 
An accurate knowledge of the length of time required for the food to 
pass the entire digestive tract has a bearing on the time at which it is 
safe to save excreta from the bird under digestion trial. The problem is 
to determine just the length of time required for food to pass through 
the entire digestive tract so that a safe allowance can be made in planning 
the taking of data of feed given and excreta saved for analyses during the 
same time. 
We also wished to determine whether the rapidity of digestion is the 
same in growing fowls, broody hens, hens not in laying, and hens in 
laying. 
EXPERIMENTAL METHODS 
Fowls of the American breeds were used in these experiments. Only 
hens were to be tested, and birds 2 to 3 years of age were selected. 
The birds were kept in small wire coops 18 inches square with i-inch 
chicken netting floor. The coop stood on a tin pan slightly larger than 
the floor of the coop. This pan was to catch the excreta as it was voided. 
Ground feeds, such as wheat middlings and corn meal, were used in 
which was incorporated a material that would stain the digestive con¬ 
tent and indicate just when the food passed out of the body. The 
indicators were lampblack, methylene blue, and gentian violet. 
THE DATA 
Test No. i.—W hite Plymouth Rock hen, leg band No. B36, weight, 5.9 pounds. 
8 a.m. Fed 20 gm. wheat middlings mixed with water and lampblack. 
2 p. m. First evacuation; a trace of lampblack appeared. 
4p.m. Still only a trace of lampblack appeared. Fed 20 gm. wheat middlings 
without lampblack. 
6p.m. Evacuation showing excreta decidedly black. 
8 a. m. Second day. 20 gm. middlings and water given. 
8 a. m. Third day. After 48 hours excreta showed slight tinge of lampblack on 
the outer surface but none on the inner particles. 20 gm. middlings mixed 
with water given. 
6 p. m. 20 gm. middlings mixed with water given. 
8 a. m. Fourth day. After 72 hours excreta normal; no trace of lampblack. 
Lampblack appeared in 6 hours and disappeared in 72 hours. 
1 Accepted for publication Jan. 16, 1922. ..... 
a Kaupp, B. F. the anatomy of the domestic fowl, p. 148, 150, fig- 31, 36, 37- Philadelphia and 
London, 1918. 
Journal of Agricultural Research, 
Washington, D. C. 
acs 
Vol. XXIII, No. 9 
Mar. 3, 1923 
Key No. N. C.-15 
(721) 
