4 BULLETIN 1069, IT. S. DEPARTMENT OF AGRICULTURE. 



tained show about the same averages as they would if 12-months 

 records only were used. The cows discarded before the end of the 

 testing year were inferior cows, which would tend to lower average 

 production, but they generally were on test during the early part 

 of their lactation period, which would tend to increase average pro- 

 duction. The figures shown in Table 1 indicate that these two in- 

 fluences nearly offset each other when large numbers of records are 

 used. 



This bulletin considers feeds chiefly from the standpoint of the in- 

 come they produce over their cost but a study is now being made of 

 the cow-testing-association records to determine the relation of feeds 

 to other factors, in which feeds of various kinds are considered by 

 quantity and feeding value. 



GENERAL AVERAGES OF PRODUCTION, FEED COST, AND 



INCOME. 



The figures in Table 1 are from the records of 120 sets of cow-test- 

 ing-association records and they compare the 12-month records 

 with all the records furnished by those associations. Tables 1 and 



5 are the only tables in which anything but 12-month records are 

 used. 



Table 1. 



-Comparison of the 12-month records with all the records studied- 

 Averages per coiv-year; period 1910 to 1920, inclusive. 





Cows on 



Cows on 





Cows on 



Cows on 





test 12 



test 4 





test 12 



test 4 





months 



months 





months 



months 





and 



and not 





and 



and not 



Item. 



whose 



more 



Item. 



whose 



more 





breed 



than 12 





breed 



than 12 





and age 



(includes 





and age 



(includes 





were 



first 





were 



first 





given. 



column). 





given. 



column). 





21,234 

 21, 234 



41, 990 

 37, 362 





$33.41 

 $21. 89 



$32. 03 



Number of cow-years x 



Average milk yield, pounds.. . 

 Butterfat test, per cent 





$21. 03 



6,077 



5,989 



Total feed cost 



$55.30 



$53.06 



4.08 



4.12 



Income over feed cost 



$62.70 



$59. 33 



Average butterfat, pounds 



248 



247 



Returns for $1 expended for 









$0.48 

 $118. 00 



$0.46 

 $112. 39 



feed 



$2.13 



$2.11 











1 A cow-year may be the record of 1 cow on test 12 months, or it may be made up of the records of 2 or 

 more cows* the sum of whose testing periods equals 12 months. 



The average milk production per cow-year for the cows on test 12 

 months was 6,077 pounds, while the average milk production for all 

 the cows on test was 5,989 pounds, a difference of only 88 pounds. 

 The average production of butterfat per cow-year was 248 pounds 

 for the cows on test 12 months and 247 pounds for all the cows on 

 test, a difference of only 1 pound. In return for $1 expended for 

 feed there was a difference of only 2 cents per cow-year. For the 

 cows on test 12 months the returns averaged $2.13 and for all the 

 cows on test the returns averaged $2.11. 



