Effect of a blend of essential oils, bioflavonoids and tannins on production performance, health, immune functionality, and antioxidant status in fattening beef cattle

The aim of the study was to evaluate the effect of a blend of essential oils, bioflavonoids and tannins on production performance, health, immune response, and antioxidant status in fattening beef cattle under field conditions. A total of 210 newly arrived male Charolaise bulls were assigned to two study groups: i) Control (417.84 +/- 19.63 kg live weight), basal diet; ii) Treatment (416.37 +/- 18.56 kg live weight), basal diet integrated with 5 g/head/d of the blend of essential oils, bioflavonoids, and tannins. Growth performances, dry matter intake (DMI), feed conversion rate (FCR), carcass characteristics and health were evaluated during the entire fattening period (182 days). The immune response and the oxidative status were evaluated at the arrival (d(0)), and after 45 days (d(45)) by the titration of antibodies against BHV-1, serum bactericidal activity, gamma-interferon levels, free oxygen radical metabolites (ROM's), and antioxidant activity (OXY). Growth performances and production efficiency resulted to be significantly improved by the treatment. Indeed, both weight at d(102) and d(182) were higher in the Treatment group (respectively 579.81 and 720.86 kg vs 572.69 and 709.82 kg in the Control) (P <= 0.05). As a result, also the total average daily gain (ADG(0-182)) (1.67 vs 1.60 kg/head/d) (P <= 0.001) and the ADG between d(0) and d(102) (ADG(0-102)) (1.60 vs 1.52 kg/head/d) (P <= 0.05) were improved. The DMI was lower in the Treatment group (10.59 vs 11.18 kg/head/d) (P <= 0.001), leading to a significant improvement in the FCR (6.37 vs 7.04) (P <= 0.001). Carcass weight was higher in the Treatment group (425.87 vs 418.31 kg in the Control group) (P <= 0.001), while carcass characteristics weren't affected by the treatment. The incidence of bovine respiratory disease (BRD) was significantly reduced by the treatment (17.14 vs 28.57 % in the Control group) (P <= 0.05). No differences were found in the incidence of lameness. The Treatment has led to an increase in the serum bactericidal activity (92.00 vs 80.40 % in the Control group) (P <= 0.05) and to a better antioxidant status (365.68 vs 290.58 mu mol HClO/ml in the Control group) (P <= 0.001) at d(45). No differences were found in terms of antibodies titration and ROM's levels. In conclusion, the supplementation of fattening beef cattle diet with a blend of essential oils, bioflavonoids and tannins, improved growth performance, feed efficiency and health status thanks to a better feed efficiency and immune functionality.