14 



MASS. EXPERIMENT STATION BULLETIN 364 



Table 6. — Weight Increase and Decrease, and Annual Production 



12. Monthly Body Weight and Monthly Egg Production 



In this study only birds in the high fecundity experiment and birds with com- 

 plete annual records were used. A total of 786 birds out of 1,309 with complete 

 records came from the e.xperiments on high fecundity. The hatching dates of 

 these birds covered a 49-day range between March 3 and April 26. Housing 

 facilities were available for 750 pullets each year in three units. The first unit 

 was made up of hatches 1 and 2 and a part of hatch 3, housed near September 1. 

 The second unit included the rest of hatch 3 and practically all birds from hatches 

 4 and 5, housed about September 15. The third unit was made up from hatches 

 6, 7, and 8, housed about September 28. All body weights were taken throughout 

 the year on the same monthly calendar date that the birds were housed. Mean 

 monthly weights for the different houses were combined to give a mean for the 

 total population each month. Both weight records and egg production records 

 cover thirteen months. 



CHA RJ 4 



MEAN MONTHLY BODY WEIGHT 



AND MEAN MONTHLY EGG PRODUCTION 



TOe BIRDS 



4.S0 

 SEPT OCT NOV. DEC. JAN. FEB MAR APR MAY JUNE JULY AUG SEPT 

 MON THS 



The graph for body weight (Chart 4) indicates a very rapid increase during the 

 first two months in the laying houses. During this period egg production ran 

 parallel with body weight. From November to March, the increase in body 



