The amounts of Delta 9,Delta 11-conjugated linoleic acid (CLA) isomers were determined in loin-associated fat samples of bulls (n = 6) and steers (n = 7) by capillary gas chromatography of fatty acid methyl ester (FAME) derivatives. The main CLA-isomer-18:2 c9,t11-provided approximately 0.76 +/- 0.15% and 0.86 +/- 0.15% of total FAME in bulls and steers, respectively. No differences (P> 0.05) were observed between the CLA isomer distribution of bulls (t9,c11, 0.026 +/- 0.014%; c9,c11, 0.015 +/- 0.008%; and t9,t11, 0.029 +/- 0.003%) and steers (t9,c11, 0.027 +/- 0.014%; c9,c11, 0.015 +/- 0.005%; and t9,t11, 0.030 +/- 0.007%).