JOMAl OF AGRICDLim RESEARCH 



Vol. X Washington, D. C, July 9, 191 7 No. 2 



A STUDY OF THE RATE OF PASSAGE OF FOOD RESI- 

 DUES THROUGH THE STEER AND ITS INFLUENCE 

 ON DIGESTION COEFFICIENTS ^mn^^, 



By P. V. EwiNG, Animal Hmbandman, and F. H. Smith, Chemist, Georgia -^~, 



Agricultural Experiment Station *" "^^^ 



INTRODUCTION 



As a result of some earlier investigations conducted at this Station ^ 

 on the association action of feeds, it was found that the digestibility of 

 the crude fiber of some feeds was apparently lowered when these were 

 fed in a ration containing certain other feeds. Our observ^ations also 

 indicated that these influencing feeds caused an increase in the rate of 

 food passage through the steer. A study of the data obtained from these 

 earlier feeding trials suggested that there might be a correlation between 

 the time required for the passage of the food through the animal and the 

 moisture content of the feces. 



Studies have been made on this earlier work with attention directed 

 especially to the relationship between the moisture content of the feces 

 and the digestion coefficients; and, in addition, essentially the same 

 digestion experiments have been repeated and similar comparisons made 

 upon these data. An attempt was made to follow more closely and 

 directly by means of rubber markers the time required for passage of the 

 food residues through the steers. Further efforts were made to deter- 

 mine the rate of passage by means of calculations based upon the intake 

 of food and outgo of feces and the alimentary-tract contents as ascer- 

 tained on slaughtering. Thus, three methods have been employed in 

 studying the rate of passage of food residues and the influence on the 

 digestion coefficients. 



I.— MOISTURE CONTENT OF THE FECES 



Although an expression for the exact time required for the passage of 

 food residues can not be obtained from the determination of the moisture 

 content of the feces, direct comparisons may be made of the relation 



' EwiNG, P. v., AND Wells, C. A. the associative digestibility of corn silage, cottonseed 

 MEAL, AND STARCH IN STEER RATIONS. Ga. AgT. Exp. Sta. Bul. 115, p. 269^296, 7 diagr. 191s- 



Journal of Agricultural Research, Vol X, No. 3 



Washington, D. C. Key No. Ga.— i 



ig 



(55) 



