FEEDING AND CARE OF HORSES 225 



at a fast pace are: (1) In trotting or galloping the rise and fall of 

 the body are much greater than in walking. Energy is wasted in these 

 movements, and hence a smaller amount is available for onward move- 

 ment. (2) At a rapid pace the work of the heart is increased, the 

 temperature rises, and much heat is lost thru the evaporation of water 

 from the skin and lungs in the eti'ort to keep the body temperature 

 normal. The proportion of the food which produces heat is thus 

 increased, while less can be converted into work. 



To keep mail-coach horses, which were pushed at top speed, in con- 

 dition, they could often be worked but one hour a day, traveling only 

 eight miles even on good roads. AVhile a pound of additional load 

 makes but little difference to a draft horse, with running horses the 

 requirement of speed makes it necessary that the weight carried (rider 

 and saddle) be as small as possible. An ounce of additional loading 

 may make a difference of a yard or more in half a mile of running. 



Influence of grade. — In going up a grade, the horse must not only 

 propel his body and the load over the ground but must also raise them 

 against the force of gravity. In ascending a grade of 10.7 ft. in 100 ft. 

 the horse expends three times as much energy per mile as when travel- 

 ing on a level road. The steeper the grade, the greater the energy 

 required. 



On the other hand, in going down a gentle incline, owing to the 

 force of gravity less energy is required than on a level road, which 

 results in a saving of nutrients. If the grade is steeper than 10 feet 

 in 100, however, the horse must expend energy in bracing himself and 

 the load against a too rapid descent and hence uses as much as when 

 traveling on the level. On a still steeper downward slope more energy 

 is expended than on a level course. Obviously, a great saving of feed 

 may be effected by a proper use of wagon brakes in a hilly country. 



II. Preparation of Feed ; Water ; Salt 



Chaffing hay. — With horses at ordinary farm work, which have 

 abundant time to chew their feed thoroly, cutting or chaffing hay prob- 

 ably does not result in sufficient saving to warrant the expense. How- 

 ever, in stables w'here large numbers of horses are kept, the hay is 

 frequently chaffed. Somewhat less is then wasted, especially if it is of 

 rather poor quality, and dust may be easily laid by sprinkling with 

 water. The grain allowance is often mixed with part of the chaffed 

 hay, which forces the horses to eat the grain more slowly and chew it 

 more thoroly. A common practice in Europe is to mix cut straw with 

 chaffed hay, more straw thus being eaten than w'ould otherwise be the 

 case. 



