Estimates Of Genetic Parameters For Direct And Maternal Effects With Six Different Models On Birth Weight Of Brown Swiss Calves

Abstract

The aim of the present study was to estimate variance components, genetic parameters and breeding values for birth weights in Brown Swiss calves. Data were collected from the Malya State Farm in Kirsehir province of Turkey from 1995 through 2006. Random effects included direct and maternal additive genetic effects, maternal permanent environmental effects with direct maternal genetic covariance and random residual effects. Variance and covariance components and genetic parameters were estimated using the WOMBAT software by fitting six single-trait animal models. Depending on the model, h(D)(2) varied from 0.13 to 0.30 for birth weight. Estimates of m(2) ranged from 0.10 to 0.14 for birth weight. The maternal permanent environmental effect was significant for birth weight and ignoring maternal effects in the model caused the over estimation of direct heritability. The present study shows the importance of inclusion of maternal effects in designing appropriate breeding programs for genetic improvement in Brown Swiss calves for birth weight.