Este trabalho foi realizado para avaliar as características de carcaça e composição química do músculo Longissimus de 32 bovinos não castrados de quatro grupos genéticos abatidos aos 14 meses de idade. Foi usado um modelo experimental inteiramente casualizado e distribuídos em quatro grupos genéticos: 1. Caracu (CAR); 2. Canchin (CAN); 3. Charolês vs. Caracu (CHC) e 4. Aberdeen Angus vs. Canchin (AAC). O rendimento e a conformação de carcaça foram menores para os animais do grupo genético CAR em comparação ao grupo genético CAN, CHC e AAC. Não houve diferença para umidade, cinzas, proteína bruta e colesterol total entre os quatros grupos genéticos. O grupo genético teve influência sobre o perfil de ácidos graxos do músculo Longissimus dos bovinos. Os bovinos com genes zebu tiveram maiores níveis de ácidos graxos saturados. Os ácidos graxos saturados representaram aproximadamente 50% da composição dos ácidos graxos do músculo Longissimus. O grupo genético teve efeito nas percentagens de ácidos graxos saturados e poliinsaturados, n-3 e n-6 e sobre a razão entre n-6 e n-3.

Carcass characteristics and chemical composition of Longissimus muscle of 32 young bulls from four genetic groups slaughtered at 14 months old were evaluated. Experimental design was completely randomized and distributed into four genetics groups: 1. Caracu (CAR); 2. Canchin (CAN); 3. Charolais vs. Caracu (CHC) and 4. Aberdeen Angus vs. Canchin (AAC). Carcass dressing and carcass conformation were lower for CAR than CAN, CHC and AAC genetic groups. No difference has been reported with regard to moisture, ash, crude protein, total lipids and total cholesterol among four genetics groups. The genetic groups influence fatty acid profile on Longissimus muscle in bulls. Cattle with zebu genes had the highest rates in unsaturated fatty acids, saturated fatty acids represented approximately 50% of total fatty acid composition on Longissimus muscle. The genetic groups presented differences in PUFA, SFA, n-6 and n-3 percentages and n-6 and n-3 ratios.

This experiment was carried out to evaluate the carcass characteristics, chemical composition and fatty acid profile of the longissimus muscle of 32 young bulls from four genetic groups: Caracu; Canchin; Aberdeen Angus × Canchin; and Charolais × Caracu, finished in feedlot and slaughtered at 22 months old. Each group was composed of eight animals. There was no difference for moisture, ash, crude protein or total cholesterol between bulls from different genetic groups. However, total lipids percentage was higher for bulls from Caracu and Aberdeen Angus × Canchin and lower for Canchin and Charolais genetic groups. Polyunsaturated fattty acids and n-6 percentage was higher for Canchin and lower for Caracu, Aberdeen Angus × Canchin and Charolais genetic groups. Canchin and Charolais × Caracu genetic groups presented higher n-3 percentage than Caracu and Aberdeen Angus × Canchin. There was no difference for the n-6/n-3 ratio among the bulls from the four genetic groups.