The aim of this study was to estimate direct and maternal genetic parameters of dystocia for Holstein heifers in Iran. Dystocia is an important functional trait in dairy production. Calving difficulty is a categorical trait and usually is recorded in five categories subjectively; it is also influenced by maternal effect, so models employed for its analysis should take these aspects into account. Linear and Threshold sire_maternal grandsire model analyses included observations on 144310 calves born from 1990 to 2004. Estimated heritabilities in linear model were 0.05 for direct effect and 0.02 for maternal effect, and by threshold model they were 0.06 and 0.03 respectively. Direct_maternal genetic correlations were moderate and negative.

R. Abdullahpour, M. Moradi-Shahrebabak, H. Mehrabani-Yeganeh, M. Sayadnejad, A. Eghbal

Proceedings of the World Congress on Genetics Applied to Livestock Production, Volume , , 24.22, 2006
Download Full PDF BibTEX Citation Endnote Citation Search the Proceedings

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.