Improving Accuracy of Heritability Estimates from Diallel and Triallel Matings in Poultry 1. Eight-Week Body Weight in Closed-Flock Strains

Abstract CONFIDENCE limits calculated for heritability estimates are crude approximations (Bross, 1950; Jerome, Henderson and King, 1956; and Graybill and Robertson, 1957). Therefore, in this report, repeatability and closeness of heritability estimates to those from a very large sample, are used as indications of methods which may be used to improve the accuracy of smaller samples. Accuracy in estimating heritabilities from small samples may be increased by improving the sample of parents, by choosing the most appropriate mating system and by measuring the performance of sufficient progeny. If the parents are a random sample from each sex of the population, the number of parents is most important for adequate sampling. At the beginning of this subject the junior author, rather arbitrarily, chose 50 sires and 50 dams as a minimum sample from the parental generation. To subdivide additive and non-additive genetic effects, it is necessary to measure sire-dam interaction. This is …