180 A MANUAL OF VETERINARY PHYSIOLOGY 



this table with the one on p. 178, it would appear that hay is 

 easier of digestion than oats. 



The digestion of oats in individual horses is just as irregular 

 as that of hay. A horse to which only 2 pounds of oats were 

 given was destroyed twenty hours later, and the stomach was 

 not completely empty. In another to which 1 pound had been 

 given 6 ounces were recovered after four hours' digestion. In the 

 following table the results of some experimental feedings are 

 recorded : 



Amount digested 

 per Cent. 



3 hours - - - - - - 45-0 



3 »• - . - 57'o 



3 „ _.-.-_ 7 o-o 



3m/- - 78-6 



These horses were fed under similar conditions, yet there is a 

 good deal of variation in the amount digested. In the next 

 table the period of observation was increased in order to see 

 whether greater uniformity would result : 



Amount digested 

 per Cent. 



4 hours Nil 



4 „ _.___. 180 



4 » 54*5 



4 »f ------ 5 6-o 



4 „ _.--.- 75-0 



These results are less regular than those of the first series ; 

 one horse digested nothing, and that is explained by a practical 

 fact capable of being turned .to clinical account. The animal 

 was of a very nervous disposition, and the experiment was 

 carried out in a strange stable, the mare being alone, whereas 

 she was used to the company of other animals. The second 

 horse in this series only digested 18 per cent. ; this also illustrates 

 a practical point in feeding — namely, the influence of a sudden 

 change in diet. This animal had not received oats for eighteen 

 months, having been fed on a patent food ; the sudden change 

 to oats for the experimental observation explains why only 

 18 per cent, had been digested. 



Arrangement of Food in the Stomach. — If a horse be fed on 

 oats, maize, hay, etc., in succession, the stomach, on examination, 

 will be found to contain these substances quite unmixed, and 

 arranged in strata in the order of their arrival, the first food being 

 in the pylorus and greater curvature, the last in the cardia and 

 lesser curvature. We have pointed out that the contents of the 

 stomach of the horse are squeezed and pressed, but never churned. 

 Tn successive feeding the material never mixes, excepting at the 

 pylorus, but keeps together from the time of its arrival until it 



