Effect of auxiliary traits on estimation of heritability of stayability

Abstract

SUMMARY Stayability being a binary trait in animal breeding needs thorough genetic analysis. For a true measure of stay ability this need to be adjusted for various production and reproductive traits. For estimation of heritability of stay ability this adjusted herdlife for production is converted to binary trait using threshold probability. The exhaustive methodology for threshold characters has been outlined by Falconer and Mackey [3]. The procedure of beta-binomial Paul and Bhatia [6] and Dempster-Lerner [2] methods have been used to estimate the' heritability of stayability in unbalanced data sets. It is seen that even small adjustment on account of production has a great effect on estimates of heritability of stayability. The unbalancedness led to estimates with large standard error. Further relative root mean square errors are also obtained and found that precision as well as accuracy of estimates are affected by adjustment of production. The results of modified beta-binomial method of estimation show some what consistency whereas for other procedures, no specific trend is seen for adjustment of data for production.