(Mther of the parent stocks. The highest production was from progeny 

 of Rhode Island Reds crossed with New Hampshires. 



Good hroilers were produced by Fj females mated to Dominant 

 White males. However, their growth rate to 10 weeks of age was not as 

 good as the progeny of New Hampshire females mated to Dominant 

 White males. 



Recurrent Selection 



A test was made at the New Hampshire Agricultural Experiment 

 Station of recurrent versus closed flock selection for improving broiler 

 qualities in the crossbred chicken (38, 40). A cross line progeny test 

 jihowed no advantage over a pure line progeny test for improving 8-week 

 body weight within a line. Crossbred progeny of 4th generation males 

 from the two selected lines mated to randombred females were heavier 

 from the recurrent line than from the closed line, but the difference 

 was not significant. 



Diallel Matings 



Additive genetic variance, in contrast to non-additive genetic vari- 

 ance such as dominance and epistasis, is most readily utilized in selective 

 breeding programs. It is desirable, therefore, to know the proportion of 

 the total genetic variance in a trait which may be attributed to genes 

 acting additively. Component estimates of non-additive genetic variance 

 for 8-week body weight were obtained from a diallel mating experiment 

 at the New Hampshire Agricultural Experiment Station. The test, which 

 was replicated over two years with two groups of birds, gave estimates 

 of non-additive genetic variation which were not significant. Thus, non- 

 additive genetic variation was not an important fraction of the total 

 variation in body weight, but it could have some small influence on it. 



Camma Irradiation 



The effect of gamma irradiation of New Hampshire fowl semen on 

 ten-week body weight, mortality, egg production, egg weight, fertility 

 and hatchability was stvidied at the West Virginia Agricultural Experi- 

 ment Station. The semen of the irradiated line was subjected to a total 

 dose of 1,500 roentgens of gamma irradiation at a dose rate of 3,600 

 roentgens per hour. Selection of breeding stock for subsequent genera- 

 tions was based entirely on ten-week body weight and data were collect- 

 ed for two generations. 



The irradiation of the semen did not affect ten-week body weight, 

 egg production or mortality to ten weeks of age. Egg size in the irra- 

 diated line was found to be less than that for the non-irradiated line, 

 and fertility and hatchability were both reduced by the treatment. 



Summary 



A critical review indicates that NE-6 was moderately successful in 

 attaining the first objective of developing and evaluating methods for 

 breeding improvement of poultry. 



The development of randombred control populations was the most 



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