Chemical and Fatty Acid Composition of Longissimus Muscle of Crossbred Bulls Finished in Feedlot

This work was carried out to study the chemical and fatty acid composition of Longissimus muscle (LM) of crossbred young bulls finished in a feedlot.After weaning (at 8 months old), the bulls were kept in a feedlot for 180 days.The bulls were kept in individual pens and fed (twice daily) with corn silage, soybean hulls, cracked corn, limestone, urea and mineral salt.The bulls were slaughtered with a final weight of 464 kg.Forty bulls were used: 10 Caracu (CAR), 10 Canchim (CAN), 10 Caracu vs. Charolais (CCH) and 10 Canchim vs. Aberdeen Angus (CAA).The percentages of moisture, ash, crude protein, total lipids, as well as the fatty acid composition, were measured in the LM.The moisture percentage was lower (p<0.05)for bulls from CAA genetic group (71.2%) in comparison to bulls from CAR (74.2%),CAN (74.9%) and CCH (74.7%) genetic groups.On the other hand, there was no difference (p>0.05)among bulls from CAR, CAN and CCH genetic groups.Ash percentage was lower (p<0.05)for CAR bulls (0.96%) in comparison with the other genetic groups.There was no difference (p>0.05)among CAN, CCH and CAA genetic groups.Similarly, there was no difference (p>0.05) in crude protein among the different genetic groups.Total lipids percentage was higher (p<0.05) for CAA bulls (5.35%) and lower (p<0.05)for CAN (1.85%) and CCH (1.41%) genetic groups.Genetic group has little effect on the fatty acid composition of Longissimus muscle of bulls.However, CLA (C 18:2 c-9 t-11) percentage was higher (p<0.05) for CAR (0.33%) and CCH (0.37%) in comparison to CAN (0.27%) and CAA (0.29%) genetic groups.Saturated, monounsaturated and polyunsaturated fatty acids, n-6 and n-3 percentages did not differ (p>0.05)among genetic groups.PUFA/SFA ratio ranged from 0.10 to 0.15, with no difference (p>0.05)among genetic groups.Similarly, n-6/n-3 ratio ranged from 12.6 to 16.3, without difference (p>0.05)among genetic groups.(