DAIRY PRODUCTS. 



75 



Important truth. Milk varies in composition with 

 cows of diliferent breeds, and with different cows of the 

 same breed. In the same herd the milk from no two cows 

 shows exactly the same percentage of butter fat. The 

 milk first drawn from the udder is very low in fat; the 

 last very high. It follows that cows should be selected 

 not only because of their yield of much milk during the 

 year, but also because of their ability to produce milk 

 with a high per cent of butter fat. 



Variation in Test. 



186. A dairyman has a herd of 25 cows. Ten of these 

 cows yield 40 pounds each daily ; another ten, 30 pounds ; 

 the remaining five, 20 pounds. 

 The fat test of the first group is 

 5.4 per cent ; of the second, 4.5 

 per cent ; of the third. 3.8 per cent. 

 What quantity of fat is daily pro- 

 duced by this herd ? 



187. Suppose the fat test of 

 the first group were 3.8 per cent 

 and of the third 5.4 per cent, the 

 second remaining just the same. 

 What quantity of fat would be 

 produced daily? 



188. When butter fat is Avorth 

 25 cents per pound, what is the 

 money value of this difference? 



189. How many cows of tlie 

 third type v/ould be required to 

 equal in butter production 10 cows of the first type in 

 problem 186? 



190. A certain quantity of milk testing 5 per cent con- 

 tains 45 pounds of fat. What is the quantity ? 



Babcock Tester Glass- 

 ware. 



a, milk pipette; b, millc bot- 

 tle; c, cream bottle; d, 

 graduate glass for the acid. 



