1910.] PUBLIC DOCUMENT — No. 31. 107 



(a) The cause or partial cause of the depression of the pro- 

 toid matter is due to the increased excretion of metabolic by- 

 products in the faeces. It has been definitely proved that for 

 every 100 grams of digested dry matter there is excreted .4 to 

 .5 of a gram of nitrogen, or 2.5 to 3.1 grams of protein, hence the 

 additional carbohydrates increase the digestible dry matter and 

 cause the excess excretion of metabolic nitrogen, which is calcu- 

 lated as undigested nitrogen. 



(6) According to Hirschler ^ an increase of the carbohydrates 

 or of lactic acid in the ration checks the action of putrefactive 

 bacteria, i.e.j, those acting upon the proteid matter, and G. 

 Gothwald " has confirmed this for herbivorous animals. 



(c) It being known that the easily soluble and digestible 

 carbohydrates are large yielders of lactic and butyric acids in 

 the processes of digestion, it seems at least possible that it is these 

 acids, when present in sufficient quantities, which check the 

 further action of the micro-organisms, and prevents their attack- 

 ing the more difficult digestible carbohydrates, such as the fiber, 

 pentosans, gums, etc. 



Alquier and Drouineau ^ state that in case of ruminants the 

 depression is caused because the food remains for a long time 

 in the digestive tract, and is subjected to the action of various 

 micro-organisms. These organisms follow the line of the least 

 resistance, and attack the sugars and other soluble carbohydrates, 

 leaving the cellulose, ligno-cellulose and pentosans, which they 

 would attack and dissolve more freely were the soluble carbo- 

 hydrates not present in excess ; hence the depression falls largely 

 upon these latter compounds. 



It is further explained that in case of the horse the action 

 of molasses in causing the depression is not due primarily to the 

 action of micro-organisms for the reason that the food remains 

 so short a time in the intestines, but to the alkaline salts, — 

 potash and soda, — which cause an increased action of the 

 intestines (peristalsis). Grandeau's work is cited, in which, 

 in an average of four trials with four different horses the first 

 faeces appeared sixteen hours after the feeding of molasses, while 



» Zeitschrift fiir physiol. Chem. 10 Bd. 1886, p. 306; also 39 Bd. p. 99; Abs. from Kellner. 



2 Journal fiir Landw. 39 Jahrgang, 1888, p. 325. 



3 Ann. de Sci. Agron. 2 Serie, 1904. Tome I., pp. 252-258. 



