276 



MASS. EXPERIMENT STATION BULLETIN 258 



Table 11 gives some information concerning the breeding ability of the females 

 used in 1925. Egg weight was appreciably above the standard of 56.7 grams, 

 or 24 ounces per dozen, except for foundation hen C 1124 and hen E 876, that 

 came from a high fecundity strain. 



Hatchability was far superior to 1924 and none of the birds fell below medium 

 hatchability. Eggs weighing about 61 grams showed higher hatchability than 

 either larger or smaller eggs. The correlation between egg weight and chick 

 weight at hatching stands out prominently. 



Hatching weights of chicks did not indicate that the sexes differed significantly, 

 or that weight could be used as a basis for distinguishing sex of day-old chicks. 



Mortality in chicks up to September first ran significantly higher in the inbred 

 groups than in the checks. Those groups closely inbred showed a mortality 

 of 50 per cent or more. These data would appear as something of an indication 

 of low vigor in the inbreds. 



The data on weight records given in Table 1 1 are too meager to be of great value'. 

 They do, however, point to a few general tendencies. In the first place, the check 

 birds tended to be heavier at a given age than the inbreds. There was no mor- 

 tahty in the laying houses for the check pullets, while the mortality for some 

 of the inbred families reached 50 per cent. There is general evidence that the 

 inbreds were less vigorous than the checks. 



Table 12 . — Record of All Surviving Daughters from the 1925 Matings 



Since only three check daughters and five inbred daughters had complete 

 records, the data in Table 12 are of Uttle value. The fact does stand out that 

 broodiness has been eliminated in large measure. All of the inbreds were low 

 in intensity, and all were low producers. There is some evidence, among the 

 inbreds, of increased uniformity in intensity, non-broodiness and persistency. 

 In general, the data show that inbreeding for three years has reduced vigor, egg 

 production, and possibly variabihty in characteristics affecting egg production. 

 No particular type of inbreeding has proved superior, and only occasionally were 

 inbred matings successful. 



