Variance components due to direct and maternal effects for birth weight of Brown Swiss cattle

Abstract

This study was conducted to estimate variance components and genetic parameters for birth weights of Brown Swiss calves. Experimental data were gathered from the records of a State Farm of Turkey (Konuklar) covering the years between 1995 and 2005. Random effects considered in this study included direct and maternal additive genetic effects, maternal permanent environmental effects with direct-maternal genetic covariance and random residual effects. AI-REML algorithm of WOMBAT software was used to estimate variance and covariance components, genetic parameters and breeding values. The general mean for birth weights of all calves was calculated as 38.12 +/- 0.006 kg. The least square for mean birth weights was calculated as 38.99 +/- 0.007 kg for male calves and as 37.26 +/- 0.008 for female calves. Direct heritability (h(D)(2)), maternal heritability (h(M)(2)), total heritability (h(T)(2)), r(AM) and c(AM) estimates were respectively calculated as 0.15, 0.10, 0.39, 0.96 and 0.13.