Breeding value for type traits in beef cattle in theCzech Republic

Abstract

The type was evaluated in 5 424 young animals of twelve beef breeds. Ten type traits were evaluated: height at sacrum (HS), body length (BL), live weight (LW), front chest width (CW), chest depth (CD), pelvis (P), shoulder muscling (SM), back muscling (BM), rump muscling (RM) and production type (PT). The traits represent two groups: (1) traits scoring body measurements and body capacity (HS, BL, LW, CW, CD, P) and (2) traits scoring muscling (SM, BM, RM, PT). These fixed effects were included in the model: breed, sex, HYS, mother’s age, linear regression on age at evaluation and average gain from birth to evaluation. Fixed effects in the model explained 40% to 60% of variability. The highest values of heritability coefficient were estimated for HS (h<sup>2</sup> = 0.51) and LW (h<sup>2</sup> = 0.50). BL had the lowest values of heritability coefficient (h<sup>2</sup> = 0.25). The values h<sup>2</sup> = 0.25–0.32 were calculated for the traits scoring body capacity (CW, CD, P). The range of values for muscling traits was h<sup>2</sup> = 0.26–0.35. The coefficient of heritability for PT was h<sup>2</sup> = 0.34. All traits scoring muscling and PT showed high genetic correlations (r<sub>g</sub> > 0.95). The traits scoring body capacity (P, CW, CD) were highly genetically correlated with muscling r<sub>g</sub> > 0.83. Breeding values were determined by a multi-trait animal model. Standard deviations of breeding values were higher in HS (s<sub>BV</sub> = 0.71) and LW (s<sub>BV</sub> = 0.84), which was connected with a different method of evaluation of these traits. They were in the range of 0.19 (BL) to 0.30 (RM) in the other traits.