Il8 FEEDING 'FARM ANIMALS 



production in the dairy cow, if in no other way than through 

 the enfeebling influence which such want of exercise would 

 exert on her entire system. The limit of the restriction 

 that may be put upon the exercise given to a dairy cow has 

 not yet been fully determined, and probably it never can 

 be to the extent of formulating any rule that will prove 

 generally applicable since it is a factor that will be influ- 

 enced by conditions which relate to breed and general man- 

 agement. That the results referred to above will tend to 

 curtail the period of possible usefulness in an animal is so 

 patent that it does not need demonstration. 



Of course the period of usefulness may be curtailed by 

 over exercise, but such exercise will seldom be taken vol- 

 untarily. If taken it is under the constraint of labor that 

 compels, as in the case of the horse, or under the necessity 

 for exercise in searching for food, as in the case of ani- 

 mals kept much of the time on pastures quite inadequate to 

 their needs. 



Extent of prolonged usefulness. There is, of course, 

 a limit to the period covered by the profitable production 

 of all animals. That period differs in the classes of domestic 

 animals and in the breeds of the same. Since it is influenced 

 by feeding, management and inheritance, it is evident that 

 the duration of this period is in a sense flexible. It may be 

 prolonged or shortened. The tendency during recent years 

 has been to shorten it through shortening the period of 

 maturity. It would seem to be easily possible to carry 

 change in this direction too far, especially for the best 

 interests of breeding, of milk production and of labor. 

 With meat-making animals it is different. The end for 

 which they are grown is the block and the age at which 

 they will bring greatest profit for this purpose, all things 

 considered, is the age when life should terminate with 

 them. 



It is entirely different, however, with breeding ani- 

 mals. The successive acts of breeding involve repetition, 

 and the greater the number of the instances of successful 



