Effect of sex and individual variation on behavioural responses and performance of Simbrah cattle

The aim of this study was to evaluate the effect of sex and individual variation on the behavioural responses and performance of Simbrah bovines subjected to a habituation process to human interaction and exposure training. Nineteen animals were used (8 females and 11 males). Reactivity was assessed through points in the restraint cage (1-5), a score for cage exit speed (1-2), and body weight in five assessments over 86 days. Linear mixed models and the effect of individual variations were adopted through a linear regression for each animal, using the b coefficients to classify the animals as habituated, neutral and sensitized. The sex of the animal did not affect the reactivity in the restraint cage, or the cage exit speed (p>0.05); however, reactivity decreased from day 16 (p<0.05) in relation to day 0 in both reactivity scores. There were individual differences in reactivity in the restraint cage and in body weight. On this, 74% of the animals became accustomed to the handling procedure, 21% showed neutral responses in the restraint challenge and 5% were sensitized. In turn, all animals gained weight at different levels, with positive, significant b coefficients (p<0.05) and R2 >0.70. In conclusion, the process of habituation to human interaction and exposure training consistently reduced the reactivity of the animals, without altering their productive performance; however, individual differences must be considered during handling procedures.