Investigation of Direct and Maternal Effects on 24 Months Weight in Indigenous Matebele Goats in Zimbabwe

Abstract

This study investigated the importance of direct and maternal effects as well as the most appropriate model of analysis for 24 months weight (24MW) of indigenous Matebele goats. Records of 2110 (1245 males and 865 females) indigenous Matebele goat kids raised over the period 1996 - 2006 from 67 sires and 512 dams for 24MW were analyzed. Direct additive and maternal genetic effects were also investigated. The data originated from Matopos Research Station, Bulawayo, Zimabwe and variance components were estimated using restricted maximum likelihood, fitting five animal models, by including or excluding maternal effects. The maternal heritability decreased from 0.52 to 0.20 when maternal genetic effects were included in the model. Maternal heritability was zero when only maternal genetic effects were included in the model and was 0.04 when permanent environmental effects of the dam were added. On the other hand, permanent environmental effects of the dam were negligible. A negative and positive genetic covariance between direct and maternal genetic effects was observed. The results showed that maternal effects were not important for 24MW and could be neglected from the model. Therefore the inclusion of maternal effects into the model for mentioned trait is unnecessary.