The light breed Cornell randombred population was produced from 

 conunercial strain crosses of White Leghorns from several different 

 sources. Every chick hatched in the first generation had at least four 

 different high producing White Leghorn strains in its background. 

 Later, hatching eggs from the Cornell randombred population were sup- 

 plied to the North Central Regional Poultry Breeding Laboratory at 

 Lafayette, Indiana. This made the population available to the NC-47 

 Regional project, and made it feasible to study possible genetic changes 

 in the two flocks maintained under two different environments. Also, 

 the possibility of a disastrous loss of the population was reduced. 



The randombred control populations have been used in the NE-6 

 Regional project to measure genetic progress in the different contribut- 

 ing projects. They have also been used in nutrition and physiology 

 experiments where a broad genetic base was needed. They have been 

 highly valued in providing genetically stabilized flocks for use as en- 

 vironmental control flocks at many experiment stations and random 

 sample poultry tests, for the estimation of genetic parameters in un- 

 selected populations, and for foundation flocks in directional selec- 

 tion experiments. Tables I, II and III provide heritabilities, genetic 

 correlations and phenotypic correlations of various traits estimated 

 from these and other poultry populations in NE-6 (27, 56). 



The Cornell randombreds have been widely used as experimental 

 material in the United States and are now maintained at the North 

 Central Regional Poultry Breeding Project at Lafayette, Indiana. Sam- 

 ples of hatching eggs from these and other light breed randombred 

 controls are available from the North Central project for experimental 

 work. The Connecticut randombred population has been discontinued 

 but other heavy breed randombred controls are maintained at the 

 Southern Regional Poultry Genetics Laboratory at Athens, Georgia. 



Mass Selection 



A 10-year mass selection experiment was conducted at the Reymann 

 Memorial Farms substation of the West Virginia Agricultural Experi- 

 ment Station (25) . The birds were pen-pedigreed only, and selection was 

 based on individual 10-week body weights and breast angle measure- 

 ments. A non-selected line was maintained as a control. 



Mass selection was effective in increasing both traits in comparison 

 with the control. The rate of increase was consistent with the genetic 

 theory of selection. 



Crossbreeding 



Earlier research had shown that crossbreeding was advantageous 

 for producing broilers. However, reproduction in meat type stocks left 

 much to be desired. Researchers at the West Virginia Agricultural Ex- 

 periment Station approached this problem by crossing meat type New 

 Hampshires with high egg producing White Leghorns, Rhode Island 

 Reds and Barred Plymouth Rocks (9, 25). The Fj crossbred females 

 were then mated to meat type Dominant White males to produce the 

 broiler chicks. 



Almost without exception, the Fj females produced more eggs than 



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