266 Breed differences in feeding behavior measured by two remote monitoring technologies in feedlot steers

Abstract Estimation of individual dry matter intake (DMI) is required to optimize feed efficiency, carcass endpoint and profitability of feedlot cattle. However, measuring individual DMI is not practical or economically viable in a commercial setting. It is suggested that feeding behavior measured by remote monitoring technologies could be used to predict DMI of feedlot steers in real-time. However, inherent differences between breeds could influence DMI and feeding behavior and therefore these may need to be considered to predict DMI from feeding behavior. The objective of the present study was to assess differences between breeds in DMI and feeding behavior using data collected from radio-frequency identification (RFID) tags linked to electronic feeders and smart ear tags with accelerometers. Twenty-four steers from each breed [Angus, Brahman and Charolais; initial body weight (BW) = 335 ± 25.0 kg/steer) were fed using 10 electronic feeders in a serial slaughter trial for up to 200 d with 50 d slaughter intervals. Data were averaged per animal and ANOVA was performed with fixed effects of breed and length of the feeding period. There was no interaction between breed and length of feeding period (P > 0.05). DMI, feeding time and visit length measured by RFID, were less in Brahman compared with Angus and Charolais steers (P < 0.05). Eating rate (g/min) was not affected by breeds (P > 0.05); however, Brahmans ate faster compared with the other two breeds when expressed as gּ min-1ּ kg BW-1 (P ≤ 0.001). Smart tags showed that daily eating and ruminating times were longest in Charolais and shortest in Brahman (P < 0.05). In contrast, time spent not active was longest in Brahman and shortest in Charolais (P ≤ 0.001). Daily ‘active’ time was longer and ‘highly active’ shorter in Angus and Brahman compared with Charolais (P < 0.001). Differences in feeding behavior suggest that breed should be considered to predict DMI from RFID and smart ear tag technologies.