280 



MASS. EXPERIMENT STATION BULLETIN 258 



Table 14 indicates that the check birds laid slightly heavier eggs which pro- 

 duced heavier chicks than the inbreds. The most significant point brought out 

 by this table is the fact that chick mortality rate increased in the check group 

 under inbreeding, and that chick mortality was decreased in one inbred pen by 

 crossing. Three hens in the inbred pens gave no chick mortality to September 

 first, and two others gave 6 and 8 per cent, respectively. Four of the hens in 

 the inbred pens did give excessive chick mortality which would indicate that 

 vigor was low even when inbred strains were intercrossed. Hen C 1124 gave 

 no chick mortahty when mated to her son as shown in the table. 



Progeny records for one year as given in Table 14 showed a higher mortality 

 rate in the laying houses for the original check pen when inbred than when out- 

 bred in previous years. The mortalit}^ rate of the check pullets in the laying 

 houses was also significantly heavier than for the inbred strains crossed together 

 in 1926. Numbers were small, however, so that too much weight should not be 

 attached to these results. 



Table 15. — Record of All Surviving Daughters from the 1926 Matings 



Dam No. 



Bird No, 



Age 



at First 

 Egg 



Weight 



at First 



Egg 



Pause 



Average 

 Winter 

 Clutch 



Total 



Days 



Broody 



Annual 

 Persist- 

 ency 



Annual 

 Produc- 

 tion 



F 525 

 F943 



C 6127 . 

 F725 



F 1449 . 



C 6286 . 



F 1488 . 



F 1589 . 



F 2147 . 



G 1218 

 G 1219 

 G 1221 



G 1241 

 G 1242 



372 

 764 

 766 

 768 



G 1331 



Days Lbs. Days Eggs 



Check Pen — Inbred 



Inbred Pen 1 



Inbred Pen 2 — Crossed 



Days Days 



357 

 198 



323 



206 

 134 



181 



201 



212 



130 

 135 

 101 

 234 



201 



142 



224 

 190 

 174 



237 

 181 



167 

 205 

 141 

 147 

 171 



The progeny test of the matings of 1926 is recorded in Table 15. Unfortu- 

 nately the number of offspring is small. The data appear to indicate greater 

 uniformity in age at first egg for daughters from the inbred pen than from the 

 check pen. Genetic early maturity seemed very well established in the daugh- 

 ters. Body weight at first egg was above breed requirements but lacked uni- 

 formity in all of the pens. Winter pause was more prolonged in the inbred daugh- 

 ters, and there were only four of them lacking this undesirable trait. In clutch 

 size every daughter but two of the inbreds was deficient. It may be said that in 



