PSIII-1 Characterization of eating pattern and animal behavior according to productive system of intensive beef fattening fed high-concentrate diets

摘要

Eating pattern and animal behavior of three different intensive beef fattening systems, combining cattle breed, gender, and fattening days were studied under the same commercial farming conditions. A total of 120 animals were allocated in 6 pens (two per treatment), and each pen was assigned to 1 of 3 treatments according to productive system: 1) Holstein bulls, slaughtered at 11.5 months of age (142 ± 3.3 days of age and 176 ± 5.5 kg of initial BW), 2) crossbred heifers at 10 months (141 ± 3.3 days of age and 165 ± 5.5 kg of initial BW), and, 3) crossbred Angus bulls at 12.5 months (154 ± 3.3 days of age and 192 ± 5.5 kg of initial BW). Each pen had two separate feeders for concentrate and straw, and a water trough. Eating pattern was recorded per day and animal, and animal behavior was analyzed fortnightly by scan pen sampling. Data were analyzed using a mixed-effects model with repeated measures. Most relevant interaction revealed that around 215 days of age (onset of puberty) heifers visited less frequently the feeder (7.5 vs 8.1 ± 0.23) and devoted more time to eat (7.5 vs 6.5 ± 0.22 min), decreasing eating rate (153.8 vs 177.4 ± 4.97 g/min) compared with bulls. Regardless of age, heifers tended (P < 0.10) to exhibit more frequently non-agonistic (20.4 vs 13.0 ± 1.53 n/15 min), less agonistic (1.2 vs 3.8 ± 0.92 n/15 min) and sexual (1.3 vs 5.5 ± 1.65 n/15 min) behaviors, and more stereotypies (1.5 vs 0.3 ± 0.08 n/15 min) compared with bulls. In conclusion, when animals spent time performing agonistic and sexual behaviors, the time devoted to eat was reduced, identifying a gender effect. This finding could have implications in terms of feeder design, number of feeding spaces, and feeder access.