Interacción semental x ambiental en la estimación de la correlación genética entre efectos directos y maternos en bovinos para carne

a precise quantification of maternal influence and genetic correlation between direct and maternal effects (rd-m) is important for the genetic evaluation of weaning weight (pd) in cattle. the aim of this study was to evaluate the effect of including sire × environment interaction (environments: herd, year, herd-year or contemporary group) on the estimation of r for pd in beef cattle. five univariate animal models were evaluated in angus (a, n=2985), salers (s, n=4343) and braunvieh (se, n=12 320) breeds. fixed effects in the initial model were the linear and quadratic covariates of cow age, and the linear of purebred degree in se; the random effects were contemporary groups, direct and maternal correlated genetic effects, and permanent environment of the cow. alternative models additionally included the sire × environmentrandom effect. analyses were performed with the mtdfreml program and the models were compared through their aic values. the rd-m estimates with the model without sire × environmentinteraction were: -0.09±0.34, -0.71±0.11 and -0.44±0.14 for a, s and se. the inclusion of any interaction improved the prediction of models in the three breeds studied, accounting for 1 to 8 % of the phenotypic variance. the inclusion of sire × contemporary group in the model resulted in rd-m of less negative magnitude than with the model without the interaction (0.87± 1.21, -0.66±0.15 and -0.31 ±0.18, for a, s and se), and generally causing better relations between the predicted direct and maternal genetic values; yet in a the could not be estimated accurately. it is advisable to include sire × contemporary group interaction in the genetic evaluation model for pd of the populations salers and braunvieh.