10 EXPEKIMENT STATION RECORD. 



weight wore actiuiUy less in propcjrtion to their size. The physiolog- 

 ical reason for this. Baudeinent believed, is that large horses, other 

 things being equal, aetuall}' change in weight less readil)' than small 

 horses, since the organs of secretion and the surface area (which serves 

 for the radiation of heat) do not vary regularly in proportion to size, 

 but are relatively larger in animals of small size, and do not perform 

 their functions as economically in small as in large animals. The 

 writer's observations have led to the same conclusions. This theor}^ 

 shows why somewhat larger amounts of protein and carbohydrates 

 are considered necessar}^ per 100 kg. live weight with small horses 

 than with large ones, and also wh\^ small animals are often given 

 rations especialh^ rich in protein. 



Although the standard rations suggested are based on a very large 

 number of estimates, they should be considered the minimum amounts 

 which will keep horses in condition and prevent premature wearing 

 out. Chardin, an army veterinarian and the author of a recent work 

 on army horses,^ gives estimates which are smaller than ours. They 

 are in effect as follows: It is probable that the average daily work 

 performed by army horses is about 700,000 kilogrammeters. Accord- 

 ing to the investigations of A. Sanson, 1 kg. of protein combined, as 

 it should be in a satisfactory ration, with 5 to 6.5 kg. of carboh^-drates, 

 would supply 1,600,000 kilogrammeters of energy; hence 700,000 

 kilogrammeters would require the consumption of -137.5 gm. of protein. 

 Oats contain on an average 12 per cent of protein. Therefore 3,645 

 gm. of oats would be required in order to furnish the necessary 437.5 

 gm. of protein. As a general rule, the rations of French army horses 

 contain about 800 gm. in excess of this amount, as is shown by the 

 official statistics published by the French Government in 1887. On 

 the other hand, the quantity of hay supplied is about 2 kg., or one- 

 third less than it should be. It must be remembered that so far only 

 external work has been considered. The internal muscular work must 

 also be provided for. The surplus amount of oats mentioned serves 

 for this but is not quite sufficient, and the deficiency is made up by the 

 straw consumed. This also serves a useful purpose in another way. 

 It increases the bulk of the ration. It is not certain, however, that 

 sufficient straw is consumed. 



This summary shows the difficulties of the problem under considera- 

 tion. It is the writer's opinion that his values are more nearly pro- 

 portional to the actual requirements than those of Chardin. 



Turning to the investigations which have been made on this subject 

 in Germany, we find that Ellcnberger's researches led to an increase in 

 the grain ration supplied to the army horse. The author recently had 

 the opportunity of personally becoming familiar with the investiga- 



^ Hygiene du cheval de guerre. Paris: Asselin & Houzeau, 1898. 



