The relation between temperament with performance and meat quality was determined in 79 Charolais × Nellore steers kept in feedlot. Temperament was evaluated according to exit velocity, scale composite score and flight distance four times in the finishing phase, along with body weight, intake and feed conversion measures. Cattle were classified as calm, intermediate and excited according to exit velocity measures at the beginning of the trial. Excited cattle presented larger values for composite score and flight distance. Irrespective of genotype, excited cattle presented lower average daily gain, dry matter intake and worse feed conversion. Temperament categories did not affect most of beef quality traits, except for calm Bos indicus steers, which presented greater pH measured 1 hour post mortem compared with more reactive steers. However, moderate but negative correlations were detected between exit velocity, flight distance and composite score and beef quality as well as Warner-Bratzler shear value, luminosity, pH measured 24 hours post mortem, although they were not consistent between genotypes raised under the same conditions.

Avaliou-se a influência da interação entre genótipos e do temperamento de bovinos sobre os ganhos diretos e indiretos para a produção de carne. Utilizaram-se 79 machos castrados com 19 a 20 meses de idade, divididos em oito grupos genéticos resultantes de cruzamentos Charolês x Nelore: 0, 25, 31, 38, 63, 69, 75 ou 100% Charolês. Os animais foram mantidos em confinamento e alimentados com uma dieta contendo 50% de volumoso e 50% de concentrado. O temperamento foi avaliado utilizando-se quatro metodologias adotadas durante as pesagens: escore composto (EC); tempo de saída (TS); distância de fuga (DF); e escore de localização do redemoinho de pêlos faciais (RED). Maiores porcentagens de sangue Charolês estiveram relacionadas positivamente ao ganho de peso diário. Independentemente do grupo genético, os animais mais reativos ganharam menos peso. O temperamento é influenciado pelo grupo genético, uma vez que animais com maiores proporções de sangue Nelore são mais agitados e excitáveis.

The influence of the relation among genotype and temperament of cattle on the direct and indirect gains for meat production. Seventy-nine steers with 19-20 mo old from eight genotype groups of Charolais x Nellore crossbred were evaluated: CH (100CH), ¾ CH1/4N (0.75CH), 11/16CH5/16N (0.69CH), 5/8CH3/8N (0.63CH), 3/8CH5/8N (0.38CH), 5/16CH11/16N (0.31CH), 1/4CH3/4N (0.25CH) e N (0CH) animals were kept in feedlot and were fed with diet containing 50:50 forage to concentrate ratio (%DM). The temperament was evaluated using are four methods adopted during the cattle weights: composite behavior score (BC), flight time (FT); flight distance (FD), and facial whorl (W) position score. Higher percentages of blood Charolais were positively related to daily weight gain. Regardless of the genetic group, the animals more reactive gained less daily weight gain. The temperament is influenced by genetic group, since animals with higher proportions of blood Nellore are more agitated and excited.