56 THE ECONOMICS OF FEEDING HORSES 



any particular animal may be classed as light , moderate, 

 or severe. The standard requirements of a 1,000-lb. 

 horse for heavy work have already been stated as the 

 equivalent of 15 lbs. of digestible starch, and this 

 amount may be reduced to 13 lbs. for moderate work, 

 and m lbs. for light work. 



The matter of speed or pace is of great importance in 

 arranging a suitable ration, for the reason that the 

 energy expended increases very rapidly with increase of 

 pace. Many experiments have been performed to deter- 

 mine the value of food for work performed at different 

 speeds, and among the most accurate are those by 

 Zuntz. He found that the food required per unit of work 

 increased nearly 70 per cent, in altering the speed from 

 three miles to seven miles per hour. In other words, 

 the performance of a given amount of work costs much 

 more in food when done at a fast pace than at a slow 

 one. In connection with pace, it is further necessary to 

 remember that the ''nitrogenous ratio" of the ration 

 must be narrow (1 : 5-5 or 6) for the best results, if the 

 work is to be done at a fast pace. This point is related 

 more or less to the question of the bulk of food for 

 different purposes. The horse at fast work, for example 

 a hunter, must have his nutriment in comparatively 

 small bulk, whereas a horse used for slow work on a 

 farm may be allowed a large bulk of less concentrated 

 food from which to extract the nutriment required. 



The duration of work — i.e., the number of working 

 hours per day — has a bearing upon the question of a 

 suitable ration, for a horse with sixteen hours out at 

 work and only eight in the stable must not waste time 

 on unnecessarily slow feeding. The sooner (within 

 limits) he clears his manger the better, for the rest of 



