Testing Milk on the Farm. 159 



as the average for all mature cows in the herd. 

 It should be remembered that a high production of but- 

 ter fat in the course of the whole period of lactation is 

 of more importance than a very high test. 



Questions. 



1. How does the test of the milk yielded by a cow generally 

 change with the advance of the period of lactation? 



2. Mention at least six causes of variations in the test of a 

 cow's milk. 



3. How is an accurate sample taken of a cow's milk? 



4. Between which limits is the test of milk of single cows 

 and of a herd likely to vary? 



5. Will it introduce any error in the test of a cow's milk to 

 measure out the sample directly after milking ?If so, how much? 



6. How many times should the milk of a cow be weighed and 

 tested to calculate the total production of milk and butter fat 

 by the cow during a whole period of lactation? 



7. What is an official test of a cow? 



8. How does the test, as general rule, change during the 

 first couple of weeks after the cows are let out on pasture in the 

 the spring? 



9. How do changes in the feed of a cow influence the quan- 

 tity and the quality of her milk? 



