Genetic parameters of conformation traits in Polish Simmental cattle

The aim of the study was to estimate genetic parameters of 6 descriptive and 21 linear conformation traits in Simmentals. The data were obtained from FedInfo, the Polish national recording system, and were provided by the Polish Federation of Cattle Breeders and Dairy Farmers. A multi-trait animal model and a Bayesian method via Gibbs sampling (BLUPf90 package) were used to estimate the genetic parameters of 6 descriptive and 21 linear conformation traits. The analysis included 1.397 recorded Simmental cows and one generation of ancestors, totaling 2.330 individuals. The cows, born between 2007 and 2017, were daughters of 115 sires.

The heritability of descriptive traits was low to high and ranged from 0.09 for feet-and-legs to 0.55 for muscularity. Among the linear traits, the highest heritability was estimated for chest circumference (0.69), front-muscularity (0.61) and rear-muscularity (0.60). Traits related to legs were lowly heritable. Descriptive traits showed moderate to high genetic correlations; all were positive and ranged from 0.23 to 0.86. The lowest genetic correlations were estimated between udder and muscularity (0.23), whereas the highest between overall conformation and both udder (0.85) and muscularity (0.86). Among the linear traits the highest genetic correlations occurred between chest circumference and chest width (0.84), front-muscularity (0.88) and rear-muscularity (0.80), as well as between chest width and both front-muscularity (0.84) and rear-muscularity (0.82). Front-muscularity and rear-muscularity were also highly genetically correlated (0.89).