The content of polyunsaturated fatty acids in intramuscular fat of beef cattle in different breeds and crossbreeds

Abstract. The effect of crossbreeding on the content of polyunsaturated fatty acids (PUFA) in intramuscular adipose tissue of the Musculus longissimus pars thoracis of slaughter bulls was studied. The differences among 8 genotypes of bulls was most significant (p<0.01) in C18:3, C20:4, C22:4, C22:5 and C22:6. The content of linolenic acid (C18:3) in the Czech Spotted Cattle (control group) was 0.526%, the highest in the Czech Spotted x Piedmont cattle crosses (0.659 %), and the lowest in crosses with the Belgian breed (0.186 %). We evaluated the content of C18:3 (n-6 and n-3) and among the genotypes the differences in the content were insignificant. Compared with the control group all the evaluated genotypes showed a higher representation of C18 n-3, which does not apply to the isomer C18 n-6. At low percent values we detected insignificant differences in changes in content of isomers C22:5. Factors such as the age of the animals and the carcass weight had no effect on the structure of fatty acids. More important was the content of the intramuscularly adipose tissues. With increasing content of intramuscularly adipose tissue the values of C18:3 (n-3 and n-6) and C22:5 (n-3 and n-6) decreased as did the content of other acids belonging to PUFA (p<0.01).