Browsing by Subject "periytyvyys"

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  • Hämäläinen, Miia-Riikka (Helsingin yliopisto, 2015)
    In Finland approximately 80 000 kg of beef is produced annually. Most of the beef originates from the dairy industry, and only a small portion comes from farms specialised in beef production. It is therefore important that in addition to beef cattle and cross-bred animals also the dairy breeds have good carcass qualities. Only then will it be profitable for the farmer to improve animal welfare. In this master’s thesis I studied the heritability of carcass qualities in Finnish Ayrshire bulls. The effect of on-farm welfare on carcass qualities was also evaluated. The studied carcass traits were muscularity (fleshiness), carcass weight and fatness. Animal welfare was measured with A-index, which evaluates on-farm welfare. The A-index has been developed to suit the needs of the Finnish beef production, and by measuring the envinroment of cows of a certain age it brings forward the differences in animal welfare between farms. The effect of genetics was evaluated by heritability and genetic variance. The statistical analysis was done using generalised linear models and the REML-method. According to the results muscularity, fatness and carcass weight have average heritability. The heritability for muscularity, depending on the model used, was 0,26–0,27. For fatness the heritability was 0,28–0,30 and for carcass weight 0,25–0,27. The traits were both genetically and phenotypically correlated; the strongest genetic correlation (0,57) was between muscularity and carcass weight. On-farm welfare seems to be connected to carcass qualities. Different versions were statistically significant to every carcass trait. Individual categories of the A-index had mainly a positive regression towards carcass qualities, which indicates that while welfare improves, muscularity and carcass weight increase as well. The only negative connection was found between fatness and locomotion abilities. Increased possibilities for locomotion thus decrease fatness. Based on the results we can deduce that by improving welfare carcass quality can be changed. This could have an impact on the income received from slaughtered animals.