Fatty acid composition of the longissimus dorsi muscle in crossbred steers fed different sources of fatty acids

The objective of this study was to evaluate the fatty acid composition of the longissimus dorsi muscle in carcasses of ¾ Bos taurus taurus ¼ Bos taurus indicus steers fed different sources of fatty acids. Thirty-six steers aged 14 months, with a mean live weight of 320 kg, were fed the following diets for 96 days: 1) control diet, containing no supplemental fat source; 2) CaSFA, diet containing 50 g calcium salts of fatty acids per kg total dry matter; 3) CS diet, containing 210 g cottonseed per kg total dry matter. The fatty acid composition of the longissimus dorsi muscle was determined by gas chromatography. No difference in slaughter weight, carcass weight, backfat thickness, or longissimus dorsi muscle area was observed between animals receiving the diets CaSFA and CS. Animals consuming the two fat-supplemented diets presented higher concentrations of oleic (C18:1), palmitic (C16:0) and stearic (C18:0) acids, corresponding to an average 80.76% of total fatty acids, and higher concentrations of vaccenic acid (C18:1 t11) in the muscle when compared with the control group. Supplementation of the diet of feedlot crossbred steers with CaSFA or cottonseed did not promote significant alterations in the lipid composition of the longissimus dorsi muscle.