Comparison of models for estimating genetic parameters and predicting breeding values for birth weight and calving ease in Czech Charolais cattle

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VOSTRÝ, Luboš, VESELÁ, Zdeňka, SVITÁKOVÁ, Alena and VOSTRÁ VYDROVÁ, Hana. Comparison of models for estimating genetic parameters and predicting breeding values for birth weight and calving ease in Czech Charolais cattle. Czech Journal of Animal Science, 2014, 59, 302-309. ISSN 1212-1819.
Year2014
CathegoryScientific publication in impacted journals
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Abstract

The most appropriate model for genetic parameters estimation for calving ease and birth weight in beef cattle was selected. A total of 27 402 field records were available from the Czech Charolais breed. For estimation of genetic parameters for calving ease and body weight, three bivariate models were tested: a linear-linear animal model with calving ease classified into four categories, a linear-linear animal model in which calving ease scores were transformed into Snell scores and expressed as percentage of assisted calving and a bivariate threshold-linear animal model with calving ease classified into four categories. All tested models included fixed effects for contemporary group (herd x year x season), age of dam, sex and breed of a calf. Random effects included direct and maternal genetic effects, maternal permanent environmental effect, and residual error. Correlations between direct and maternal genetic effects within-trait were negative and substantial for all tested models (ranging from -0.574 +/- 0.125 to -0.680 +/- 0.141 for calving ease and from -0.553 +/- 0.122 to -0.558 +/- 0.118 for birth weight, respectively), illustrating the importance of including this parameter in calving ease evaluations. Results indicate that any of the tested models could be used to reliably estimate genetic parameters for calving ease for beef cattle in the Czech Republic. However, because of advantages in computation time and practical considerations, genetic analysis using SC-LM (transformed data) is recommended.