Differences in water consumption and temperament of young Nelore and Canchim bulls raised on tropical pastures revealed by electronic monitoring

Abstract

Electronic animal monitoring devices have been tested to increase the productivity and sustainability of agricultural and food systems. For this reason, the study aimed to evaluate traits related to the use of water resources and the expression of temperament of young bulls of two breeds raised in tropical pastures using precision instruments. The experiment was conducted in São Carlos, Brazil, over 152 days. Sixteen bulls of the Nelore (NEL, Bos indicus; n=8) and Canchim (CAN, 5/8 Charolais x 3/8 Zebu; n=8) breeds were used (13.7±1.5 months; 283.0±31.6 kg BW). The animals were housed in pasture-based production systems and had ad libitum access to electronic water fountains that were continuously monitored. Temperament assessment took place in a management corral using accelerometers to measure the intensity and frequency of the animals' movements. Mean values were compared using the t-test and Mann-Whitney test, and correlation was calculated using Pearson's test (RStudio, P<0.05). The frequency of daily visits to the water fountain was 7.4% lower in the Canchim animals. However, these animals had a higher daily water intake (NEL: 15.1±8.8 vs. CAN: 20.9±10.2 L/day; P<0.05). Nelore animals had a more reactive temperament (NEL: 1,296 vs. CAN: 1,056; P<0.05). There was a significant correlation between reactivity and daily water intake. The electronic recording thus made it possible to determine a substantial influence of genotype on the pattern of water intake and temperament of the animals, information that can be very useful for the management of pasture-based production systems.