FIFTIETH ANNUAL CONVENTION 15 



INFLUENCE OF SEASON OF FRESHENING ON PRO- 

 DUCTION AND INCOME FROM DAIRY COWS 



(By J. C. McDowell, Dairy Husbandry, Dairy Division, 

 Bureau of Animal Industry). 



There is a widespread belief that cows produce more 

 milk and butterfat, and that they produce more economic- 

 ally, if they freshen in the fall or winter than if they fresh- 

 en in the spring or summer. Tabulations of cow-testing- 

 association records show that a definite relation does exist 

 between season of freshening and other factors, but that 

 the relation is not the same everywhere and under all con- 

 ditions. That relation seems to depend to some extent on 

 cost of feed, condition of pastures, and geographical loca- 

 tion with reference to markets. 



Under such circumstances a study of averages for a 

 large number of cow-testing associations taken indiscrim- 

 inately might be misleading unless followed by a further 

 study of the records of each association. The conclusions 

 given in the following pages are based on averages of the 

 records of 64 associations combined, and on averages of 

 the records of each association. The figures cover the period 

 1910 to 1920, inclusive. From each association the records 

 used were for one year only. To avoid possible error due 

 to incomplete data or to short-time tests, records were dis- 

 carded if the breed and age were omitted or if the cow 

 was on test less than 12 months. Tabulations on breed and 

 age showed that these were not factors influencing the con- 

 clusions drawn in this bulletin. In the 64 associations stud- 

 ied there were on yearly test 10,870 cows whose age and 

 date of freshening were given. The computations in this 

 bulletin are based on the records of these cows. Cost of 

 feed and price of product are based on actual figures as 

 given by the testers on the individual cow record sheets. 



