Concentrate levels of crossbred bulls slaughtered at 16 or 22 months: Performance and carcass characteristics

This study was performed to assess the animal performance of 97 bulls, 1/2 Puruna~ vs. 1/2 Canchim, that were slaughtered at 16 (16M) or 22 (22M) months with three concentrate levels (0.8, 1.2, and 1.6%) of body weight (BW). The initial body weight was lower for the 16M bulls. The final body weight and hot carcass weights were similar between the two slaughter ages. The hot carcass dressing was higher for 22M bulls. The average daily gain was higher for 16M bulls. The feed intake and dry matter feed conversion were similar between 16 and 22M bulls. The carcass length, marbling, and bone percentage were lower for 16M bulls. However, the Longissimus dorsi muscle area was higher for 16M bulls. The leg length, cushion thickness, fat thickness, conformation, colour, texture, muscle percent, and fat percent were similar between 16 and 22M bulls. The final and hot carcass weights were lower for bulls that were fed with 0.8% of BW. The carcass dressing was similar for the three concentrate levels. The average daily gain was higher for bulls that were fed with 1.6% of BW of concentrate and lower for those that were fed with 0.8%. The concentrate levels had no effect on carcass characteristics, feed intake, and dry matter conversion

Essential oils in the diet of young bulls: Effect on animal temperament.

Plant extracts and essential oils can be alternative products to antibiotics, because several plants produce secondary metabolites with antimicrobial properties. Additionally, they may act on the olfactory system, which sends signals to the central nervous system releasing endorphins that may affect the feeling of an animal''s welfare while altering an animal''s temperament. This study was conducted to evaluate the animal temperament of 40 young crossbred bulls (one-half Brown Swiss and one-half Nellore) 10 ± 2.2 mo old with an average BW of 219 ± 11.7 kg. Young bulls were randomly assigned to 1 of 5 diets: control, which had no clove or cinnamon; clove leaf included to supply 3, 500 mg/animal per day; clove leaf included to supply 7, 000 mg/animal per day; essential oil of leaf cinnamon to supply 3, 500 mg/animal per day; or essential oil of leaf cinnamon to supply 7, 000 mg/animal per day. The animal temperament was evaluated by calculating the chute score, exit score, and temperament score for periods (each 28 d during 6 periods) and among diets. The data were submitted to an ANOVA using GLM procedures with SAS version 9.0. The diet and period were considered fixed effects, whereas the animals were considered a random effect. Differences between means were evaluated using a Tukey test of 5% of significance. The addition of clove or cinnamon essential oils did not alter (P > 0.05) animal temperament. The analysis of temperament score (P = 0.55), chute score (P = 0.71), and exit score (P = 0.06) did not show significant differences among the diets. The exit score was similar among the 6 periods (1.57, 1.80, 2.98, 2.02, 2.73, and 2.66, respectively); however, chute score and temperament score were greater (P < 0.001) in the first period compared with other periods. The values for chute score were 1.85, 1.40, 1.35, 1.33, 1.20, 1.17, respectively, and the values for temperament score were 2.31, 1.81, 1.67, 1.69, 1.50, and 1.56, respectively, for periods 1 to 6. The results of this study suggest that clove and cinnamon essential oils can be added as an additive in high-grain finished diets without changing the animal temperament