Browsing by Author "Vehkaoja, Senja"

Linear classification is used in cattle breeding to estimate animal’s production traits. Classification can be done early for a young animal. Muscularity scores in classification are used to estimate the animal’s slaughter traits. During slaughter, carcasses are scored based on muscularity, fatness and weight. The price of the carcass is based on these scores, so it is important for the farm’s profitability to improve slaughter traits. If conformation scores are used to make breeding decisions to improve slaughter traits, those classification scores need to correlate with the slaughter scores both phenotypically and genetically. Phenotypic scores are important especially when choosing animals for breeding because breeding values are not calculated for conformation traits in Finland. The aim of this study was to estimate phenotypic and genetic correlations between Finnish linear classification scores and slaughter scores in beef cattle. Phenotypic correlations were estimated for Angus, Hereford, Charolais, Limousin and Simmental. Genetic correlations were estimated for Hereford and Charolais. Phenotypically the strongest correlation in every breed was between inner thigh width and slaughter traits (-0.20-0.71). Weakest phenotypic correlation in every breed was between thigh length and slaughter traits (0.01-0.21). Genotypic correlations were similar compared to phenotypic correlations in Hereford and Charolais breeds. In both breeds the correlation between hip height and carcass conformation was negative (-0.11 and -0.20), but the genetic correlations between inner thigh width and muscularity score and carcass information were strong positive (0.48-0.81). Phenotypic correlations estimated simultaneously with genetic correlations were also similar but significantly weaker compared to straight phenotypic estimations. That’s possibly because the data used in straight phenotypic estimations was more narrowed compared to the data used in genetic estimations. Heritabilities were estimated for the traits used in genetic correlation estimations. Those estimated heritabilities were moderate (0.18-0.39) in both Hereford and Charolais breeds which is similar result to earlier studies. Based on this research, linear classification muscularity scores can be used as a reliable indicator trait when choosing animals for breeding to improve slaughter traits, especially carcass conformation.