FACTORS INFLUENCING MILK PRODUCTION 309 



which event they may each be tested the same day, as a 

 rule but one herd a day is visited. The number of tests 

 in a month, however, will depend on the size of the associa- 

 tion, which should not consist of over 26 herds. On July 1 

 1921, the 452 associations in the United States had 11,209 

 members, and the herds averaged 17.3 cows each. 



PRODUCTION. 



Of the Average Cow ititke United States 

 and Dairy Countries 



y 



kBi fi ""* cw 37,384 18& 



^Dist of Columbia 



NY-Mass -Oregon- Wis. 

 WaKo-Me.-Mvnri-Nev.-Na- 



Alias. 



Pr.p.re4 by th. Ddr TUtta. 

 U. S, Department o< Agricultut*.' 



Figure 132. Showing the milk production of the average cow in the United 

 States and dairy countries. 



WHAT DO YOU KNOW ABOUT 



1. The dairy cow as a producer of digestible food? 



2. The relative merits of beef and dairy cows in milk production? 



3. The composition of Jersey and Holstein-Friesian milk? 



4. The effect of the cow's age on milk production? 



5. Decreased milk flow and stage of lactation? 



6. Securing high butter-fat records in official testing? 



7. The effect of different foods on the flavor of milk? 



8. The effect of the milking machine on production? 



9. How the fat content of milk is determined? 



10. Cow-testing associations? 



VISIT SOME DAIRY HERDS AND 



11. Note the type of cows being milked. 



12. Determine what breeds are in most favor. 



13. Learn what per cent of the cows are over eight years old. 



14. Study the milk sheets in the stable. 



15. Note the rations being fed. 



16. If milking machines are used, ascertain with what success. 



17. Compare, if possible, some tested with untested herds. 



