Effect of breed and age on beef carcass quality, fatness and fatty acid composition

Abstract. The aim of this research was to determine differences in beef carcass fatness and in the fatty acid composition of muscle and adipose tissue of three different breeds slaughtered at the age of 14 months and 19 months. The breed significantly affected the muscle fat content, carcass subcutaneous fat tissue thickness and fatty acid composition of the muscle and subcutaneous fat tissue. Different age at slaughter had no significant effect on analysed traits. The muscle tissue of the Herefords contained a higher (P < 0.05) percentage of C14 : 0 and C16 : 0 fatty acids and fewer long-chain fatty acids than the Simmentals and Charolais. The subcutaneous fat tissue of the Simmentals contained a higher (P < 0.05) percentage of PUFA, PUFA/SFA ratio and n-6 fatty acids. When fed with a high-energy diet, the Herefords proved to have the most fattened carcasses and the highest content of saturated fatty acids in the muscle. Changes in the diet of feedlot cattle should result in a more favourable fatty acid composition.