426 THE FEEDING OF ANIMALS 



animal are often the limitation of the fanner's profits. 

 Within each species varietal and individual differences 

 determine the rate of production and also whether the 

 food shall be transformed into poor milk or rich milk, 

 inferior beef and mutton or superior meat products, fine 

 wool or coarse, trotters or draft horses, and small eggs or 

 large ones. 



The selection of animals should have reference to 

 three general factors, which largely fix the rate and 

 character of production, viz., breed, individuality, and 

 age. 



512. The selection of cows. — ^The breed and indi- 

 viduality of the cow largely determine the quality of her 

 product and the quantity of production from a unit of 

 food. Neither heavy feeding nor skill in compounding 

 rations can be made the means of causing her to overstep 

 her constitutional limitations. 



The selection of cows simply with reference to breed 

 is a question of adaptability. If the production of milk 

 at the minimum food cost for a unit of volume is the 

 result most desired,, the dairy breeds characterized by 

 milk with a low proportion of solids should be chosen; 

 but if the object is merely to secure butter-fat with the 

 lowest possible food expenditure, the so-called butter 

 breeds are in general to be preferred. 



When the chief consideration is the manufacture of 

 milk solids most economically, we must deal not so much 

 with breeds as with individuals. In fact, with all breeds 

 and with animals of no breed, individual capacity is the 

 consideration fundamental to profitable feeding. Some 

 Holsteins will return both more milk and more butter 

 for a unit of food cost than will some Jerseys, and the 

 reverse is equally true. There is no magic in heredity 



