644 Journal of Agricultural Research voi. xin. No. u 



Table IV. — -Extent of comminution in early stages of digestion and effect of absorption 



in later stages 



(Figures represent changes effected in reducing proportion of feed residues from above 2 mm. to below 2 mm.] 



Stage of digestion. 



Mastication and one-half rumen and retic- 

 ulum 



One-half rumen and reticulum 



One-half omasum .' 



One-half omasum 



One-half abomasum 



One-half abomasum 



One-half small intestines 



One-half small intestines 



One-half large intestines 



One-half large intestines 



61. I 



7.8 



4.8 

 16. 2 



- 6.6 



0.7 



49-5 

 14-5 



7-3 



IS- I 



- 5-0 

 7.0 



57-1 

 19. 2 



2.7 



16. o 



— 21. o 

 -6.8 



43- I 

 35-2 



2. o 



8-5 



- 7.0 



- 1.7 



Table V. — Calculated amounts of comminution taking place in the several organs during 



digestion 



Organ. 



Rumen and reticulum (including mastica 



tion) 



Omasum 



Abomasum 



Small intestines 



Large intestines 



65.8 



6.3 



10.5 



4.8 



-2.6 



58.5 



10. 9 



11. 2 

 5-1 

 4-5 



70.9 



10. 9 



9.4 



-2-5 

 -17-3 



39. o 



[8.6 



5-3 

 .8 



"?. 2 



In making these observations on the extent of comminution in the 

 rumen it should be noted that a portion of the last half-feed had un- 

 doubtedly not been ruminated. This discrepancy would not apply be- 

 yond the rumen and recticulum to an appreciable extent. The extent 

 of comminution that takes place in the rumen and reticulum is in re- 

 verse order to the extent of comminution as a result of mastication. The 

 most complete mastication occurred with ration i, which was made up 

 of a small amount of silage, while it is with this ration that the least 

 comminution in the rumen and reticulum is indicated. The largest 

 amount of comminution in the rumen and reticulum is in ration 4. 



COMMINUTION IN OMASUM 



In general, the amount of comminution that takes place in the oma- 

 sum is rather constant, ranging from 6.3 to 18.6 per cent, the greater 

 amount taking place with those rations made up of silage and cotton- 

 seed meal, and the least amount in the ration containing the smaller 

 amount of silage alone. 



