378 



VETERINARY PHYSIOLOGY 



faeces after twenty-two to thirty hours. Some idea of the 

 distribution of the contents of the alimentary cunal is afforded 

 by an observation of Colin's : 



In the Stomach ... .5 kilos. 

 ,, Small Intestine .... 7'5 

 ., Caecum ... . 11 

 Colon 36-2 



Some interesting observations have been made upon the 

 removal of a great part of the large intestine in the rabbit. 

 It has been found that the digestion and utilisation of proteins 

 is not decreased, but that the digestion of the cellulose is 

 markedly decreased. 



The faeces of the horse are passed in rounded yellow masses. 

 They contain about 76 per cent, of water, 3 per cent, of ash, 

 largely composed of silica from the husks of grain and partly 

 of phosphates of soda, potash, lime and magnesia, and about 21 

 per cent, of organic matter, such as cellulose, lignin, and other 

 undigested vegetable remains, unabsorbed proteins, carbo- 

 hydrates, and fats, indol and skatol, and the various constituents 

 of the faeces of a fasting animal. 



They are acid, from the presence of organic acids, and they 

 contain so much gas that they float in water. 



The amount of faeces depends upon the food taken on an 

 average about 15 kilos are passed per diem. 



The question of how far cellulose is available as a food, of 

 how far it acts like other carbohydrates, has not been satis- 

 factorily demonstrated. But the most recent experiments upon 

 rabbits and upon sheep seem to show that pure cellulose may 

 replace starch as a protein sharer. When, however, it is eaten 

 mixed with the encrusting substances of the cell wall, the work 

 of digestion seems to be so great that little of its potential 

 energy is available. 



C. Intestinal Digestion of Ruminants 



Intestinal digestion is not so important in ruminants as it 

 is in horses, for digestion in the stomach is much more 

 complete. It is essentially the same in character, and cellulose 

 is more completely dissolved in these animals than it is in 

 the horse. 



