WORK PRODUCTION 



567 



According to Wiist 1 a horse weighing 1000 pounds is capable 

 of performing daily about two million kilogram meters of work, 

 inclusive of that of locomotion. Allowing for the work of 

 locomotion, this seems to agree well with Thurston's statement : 2 

 " It is customarily assumed that a horse may develop 22,500 

 foot-pounds per minute throughout a day's work of eight hours." 

 If this may be regarded as full work and if the average net 

 efficiency of the animal be taken as one- third, the net energy 

 requirements for the work itself and the total requirements, 

 inclusive of maintenance, would be as follows : 



TABLE 161. NET ENERGY REQUIREMENTS OF THE HORSE 



It should be noted that the discussions of the foregoing pages 

 apply specifically to the work horse and the results have only 

 a limited application to the feeding of pleasure or race horses. 

 With such animals, the cost of feed is economically a very 

 minor factor and success depends on experience and skill 

 rather than on mathematical computations. That a fairly 

 liberal supply of protein in rations for fast work is indicated 

 by physiological considerations has been already pointed out 

 (667). 



675. Comparison with power plant. As stated (670), no 

 satisfactory direct determinations of the over-all efficiency of 

 work animals are recorded, but it may be computed in a case 

 like that used as an illustration on a previous page (672, 673). 

 There the total useful work was 2.830 Therms, while the gross 

 energy of the computed ration would be approximately 55.800 

 Therms and the over-all efficiency, therefore, 2.830 -r- 55.800 = 

 5.1 per cent. As was shown in 2 (649) to be the case with the 



1 Cited by Kellner, Die Ernahrung der landw. Nutztiere, 6th Ed., p. 465. 



2 The Animal as a Machine and a Prime Motor, 1894. 



