CATTLE 



359 



Leading dairy breeds. Among the best-known 

 breeds of dairy cattle are the Holstein, or Holstein-Friesian, 

 as they are officially named ; the Jersey ; the Guernsey ; and 

 the Ayrshire. The Shorthorns are also a favorite class, 

 combining in large degree both dairy and beef qualities. 

 Records kept for one year in various experiment stations of 

 the United States Department of Agriculture show the fol- 

 lowing average ratings as milk producers of the first four 

 of these breeds in the station herds: 



6. Feeding Dairy Cows 



Just as the soil must contain the food elements needed 

 in the growth of the plant, so the dairy cow's rations must 

 contain the elements required to produce milk and upbuild 

 the body. If proper food is not supplied, either the amount 

 of milk or its quality will be sure to suffer. Only three 

 different food elements, or nutrients, are likely to run short 

 in the ordinary rations of the cow; these are (1) protein, 

 (2) carbohydrate, and (3) fat. 



Protein. Protein is required in the animal body for 

 the making of all muscular parts, blood and connective 

 tissue. It supplies nearly one-third of the solid part of milk, 

 going to form the curd and albumen. 



It is fortunate that the nitrogenous plants so valuable 

 in building up the soil are also rich in protein. Alfalfa, 



