Genetic correlations of tibial dyschondroplasia incidence with carcass traits in broilers

Relationships among the incidence of tibial dyschondroplasia (TD) with 7-wk live BW, carcass component weights (CCW), and abdominal fat weight (AFW) were assessed using high and low incidence of TD lines developed by a seven-generation divergent selection experiment, along with a randombred control line. The incidence of TD exhibited negative genetic correlations with both BW (-.65 and -.46 estimated from sire's and dam's components of variance and covariance, respectively) and with CCW (< -.28). The incidence of TD and AFW was not correlated based on sire's components of variance and covariance. The correlation of TD incidence with AFW was not as high as with the other traits under consideration based on dam's components of variance and covariance. Correlations of AFW with CCW were negative based on sire's components of variance and covariance, but positive based on dam's components of variance and covariance. Heritabilities of TD, BW, AFW, and CCW estimated by sire's variance components were lower than those estimated by dam's variance component. Dams might have a greater influence on TD incidence than sires. Selection for decreasing TD incidence should be feasible while simultaneously increasing BW and CCW in broilers.