BUREAU OF ANIMAL INDUSTRY. 211 



DAIRY DIVISION. 



The work of the Dairy Division, under Dr. C. W. Larson, chief, 

 has been carried out in accordance with the policy of laying special 

 emphasis on research problems. The results of investigations in pro- 

 duction and manufacturing are encouraging. Attention was devoted 

 to fundamentals, and some new discoveries were made which have a 

 direct and practical bearing upon the efficiency of production, sani- 

 tation, and utilization of dairy products. New principles were intro- 

 duced where it was thought that these principles were worthy of 

 being given field trials, and tried principles were taken into new fields. 

 The usual regulatory work of the division was continued. 



DAIRY INTRODUCTION. 



COW-TESTING ASSOCIATIONS. 



The tabulation and study of cow-testing association records were 

 continued. The records show that in well-managed associations there 

 is a gain in average yearly production per cow from year to year. 

 For example, the average production of butterfat per cow in three 

 associations (one each in Michigan, Ohio, and Pennsylvania) was as 

 follows : First year, 237 pounds ; second year, 255 pounds ; third year, 

 278 pounds; fourth year, 292 pounds; fifth year, 305 pounds. The 

 fifth-year average production was 68 pounds above that of the first 

 year. At 40 cents a pound this increase of butterfat would have a 

 value of $27.20, and for a herd of 20 cows the increased value would 

 be $544. 



The production records of 17,405 purebred, grade, and scrub cows 

 showed that in milk production the purebreds and grades excelled the 

 scrubs by 12.42 per cent and in butterfat production by 17.86 per cent. 



Other studies of association records and comparisons between such 

 records and those of the Government dairy farm at Beltsville, Md., 

 are under way, but have not advanced far enough to warrant pub- 

 lication. 



COOPERATIVE BULL ASSOCIATIONS. 



Preliminary reports indicate that the number of active cooperative 

 bull associations increased about 15 per cent during the year. In 

 Idaho the number increased from 9 in 1922 to 29 in 1923. The value 

 of using good bulls on the association plan is indicated by the com- 

 pilation of data on the milk and butterfat production of daughters of 

 association bulls as compared with the dams of those daughters. 

 Seventy such daughters whose records have been compiled showed an 

 average increase, over their dams, of 22.22 per cent in milk produc- 

 tion and 25.21 per cent in butterfat production. 



CREAMERY MANAGEMENT. 



The efficiency of creamery operation has been studied through the 

 unit cost of manufacture of the various products made at the Grove 

 City Creamery, Grove City, Pa. Data on the various phases of this 

 problem have been collected, tabulated, and summarized and a report 

 prepared. This study has been completed at Grove City, but will be 

 continued at other plants. 



