34 MILK PRODUCTION COST ACCOtTNTS 



AGES OF COWS IN COW-TESTING ASSOCIATIONS — Continued 

 Name of Association. Year. 2 3 4 S 6 



Sparta, Wisconsin 1909-10 40 31 27 31 24 



Stanley, Wisconsin 1912-13 3 28 34 39 37 



Tomah, Wisconsin 1909-10 21 36 35 31 31 



Waukesha, Wisconsin 1909-10 7 19 26 22 16 



Waupaca, Wisconsin 1913-14 58 47 36 54 21 



Waupaca, Wisconsin 1914-15 78 102 55 48 45 



Waupun, Wisconsin igii-12 47 39 29 31 35 



West Salem, Wisconsin 1909-10 40 44 s^ 4° 32 



West Salem, Wisconsin 1910-11 25 49 33 44 42 



Whitewater, Wisconsin 1909-10 23 39 38 18 29 



Wiltse, Wisconsin 1913-14 44 31 42 65 42 



Total 1916 2,353 1,962 1,821 1,641 



It will be noticed that there is an increase in the number of 

 three-year-old over the two-year-old cows. This is accounted 

 for by the fact that some are not bred to enter the herd until 

 three years or almost three years old. In order, therefore, to 

 get a figure for the probable number leaving the herd the 

 first year, an average may be taken of the decrease between 

 three years and six years as the decrease between two and 

 three. This is found to be 237. In some sections a larger 

 proportion of two-year-old cows are discarded during the fol- 

 lowing year than in others. Some discard heifers the first 

 year if they do not produce a certain amount of milk, while 

 others give the cows a longer trial. Assuming therefore that 

 the decrease between two and three is 237, the calculation 

 may be continued as follows: 



Enter at two 1,916 



Enter at three 674 



Total enter 2,590 



Assumed decrease between 2 and 3 237 



Number 3 years of age 2,353 



The next step is to get the average age at entry. Some 

 dairymen make it a practice to have the heifers freshen at 



