Table 3- 



VARIABILITY IN EGG PRODUCTION 



-Body Weight Increase or Decrease in Relation to 

 Annual Production. 



Coefficient of Variation of Means — Per Cent 



9.86 + .39 11.09 + .72 



House Temperature 



Graham (1930) presented data suggesting that house temperature and egg 

 production seem to vary together. His data show in general that a fluctuation 

 in house temperature is hkely to be followed by a fluctuation in the production 

 of the birds. Smith (1930) reported that higher house temperatures within 

 limits increased winter egg production. 



In the charts the relation of house temperature to egg production is shown. 

 The weeldy percentage production together with the mean daily house tempera- 

 ture are illustrated graphically for the laying years 1926-27, 1928-29, 1929-30 

 and 1930-31. The period begins September 11 and closes November 26 each year. 



Mean house temperature readings were taken at 7 A.M. and 6 P.M. daily 

 with thermometers located on the roost level immediately in front of the roosts. 

 The mean daily house temperature used in the charts is the mean of the two 

 readings. 



The birds of the three lines are combined on the charts. Only those individuals 

 that lived throughout the period each year are included in the production graph. 

 The number of birds included each year is as follows: hatched in 1926, 34; hatched 

 in 1928, 109; hatched in 1929, 28; and hatched in 1930, 44. 



