Essential oils in the diet of young bulls: Effect on animal performance, digestibility, temperament, feeding behaviour and carcass characteristics

With the increase of public concern over the routine use of antibiotics in livestock, the addition of plant extracts and essential oils (EOs) became a natural alternative in the diets since it might have similar antimicrobial properties as the ionophores. This study was conducted to evaluate the animal performance, temperament, feeding behaviour and carcass characteristics of 40 young crossbred bulls (½ Brown Swiss - ½ Nellore) at 10 ± 2.2 months of age with an average body weight of 219 ± 11.7 kg without (control) the addition or with different levels (3.5 or 7.0 g/day per animal) of clove or cinnamon EOs in the diet. The finishing period in the feedlot was 187 days. Animal performance was higher (P < 0.05) in the group with EOs (both levels) than in the control group diet and increased linearly when EOs was added (P ≤ 0.05). The feed intake of dry matter and other nutrients was higher and increase linearly (P < 0.05) in young bulls fed with EOs independently of the type or dosage level. Feed efficiency and the digestibility in vitro were unaffected by dietary treatment (P > 0.05). The addition of clove or cinnamon EOs did not alter (P > 0.05) temperament or feeding behaviour. The cold carcass weight was higher (P < 0.05) in bulls from the EOs groups than in the control group. However, the carcass weight was similar (P > 0.05) between young bulls with EOs received clove or cinnamon in the diet. The muscle, fat and bone percentages and fat thickness, marbling, Longissimus muscle area and pH did not differ (P > 0.05) among diets. The results indicate that the EOs improved the animal performance of young bulls finished in high-concentrate diets did not alter carcass characteristics, temperament or feeding behaviour.