THE BREEDING OF HORSES 201 



However, the average farmer must either breed Ms working 

 mares or work his brood mares. The question which confronts 

 him is how to secure natural conditions for his mares while per- 

 forming artificial service. 



It must be borne in mind that feed furnishes energy and 

 tissue-forming material, and that the performance of work re- 

 quires energy and uses up tissue. Thus the balance between 

 them is maintained. The mare at work is just as well off, in the 

 matter of exercise, fresh air, and sunshine, as the one at pasture, 

 but she has imposed upon her labor which demands more energy 

 and uses more tissue^building material. She is also subject to 

 fatigue, mechanical injuries, and nervous disturbances that never 

 come to the mare at pasture. 



Exercise and Work. — In general, the management of the 

 brood mare should have for its object the feeding of such a ration 

 as will supply the demand for energy and tissue and still allow 

 ample nourishment for the development of the foal, either before 

 or after birth, together with such a regulation of the work as 

 will protect the mare from becoming tired, overheated, or in- 

 jured in any way. She must not be fretted either by another 

 horse or by a rough hand, while heavy, jerky pulls, extreme 

 speed, rough saddle work, or jumping are to be strictly prohibited 

 as pregnancy advances. But to work a mare up to within a 

 month of foaling and then confine her in a stall with no exercise 

 whatever is almost as injurious as to begin working her hard 

 after ten months' rest, following breeding. It is not unusual for 

 mares to foal, successfully, while in the field at work, but it is 

 safer to gradually diminish the work, so that during the last 

 few weeks of pregnancy only the lightest work is done or exercise 

 in the yard is taken. 



Avoid Extremes. — It is a peculiar fact that, while the two 

 extremes in condition are both unfavorable to breeding, statistics 

 indicate that the birth rate among nations has shown a marked 

 increase following devastation by war and famine, conditions 

 of life in which the females become reduced to the extreme of 

 low condition. This would seem to be in response to a natural 

 law for the preservation of the race, and should not be taken to 



