The aim of the present study was to evaluate the effect of a pool of enzymes and beta-glucans deriving from the fermentation of Aspergillus oryzae and Lactobacillus, on in vivo digestive efficiency, production performances and health status in fattening beef cattle under field practical conditions. Two specific trials were set up. In the Trial I, 80 newly arrived male Charolaise beef cattle were assigned to two study groups: i) Control (391.23 +/- 16.54 kg live weight), basal diet; ii) Treatment (392.54 +/- 15.94 kg live weight), basal diet integrated with 5 g/head/d of the pool of enzymes and beta-glucans. The in vivo apparent total tract digestibility (aTTD) was evaluated comparing chemical composition of the diets and relative faeces, analysed with a portable NIR instrument, at d(90) and d(180) of the 185 days of fattening period. In Trial II, 306 newly arrived male Charolaise beef cattle were assigned to two study groups: i) Control (388.26 +/- 17.58 kg live weight), basal diet; ii) Treatment (388.16 +/- 15.82 kg live weight), basal diet integrated with 5 g/head/d of the pool of enzymes and beta-glucans. Growth performances, feed intake, feed conversion rate, carcass characteristics and health status were evaluated during the entire fattening period (205 days). In Trial I, the Treatment has led to a significant improvement in the digestibility of neutral detergent fiber (NDF) (P= 0.0001), cellulose (P=0.02), hemicellulose (P=0.03) and starch (P<0.0001). In Trial II, the Treatment significantly improved average daily gain (P<0.05), final weight (P=0.005), and feed conversion rate (P<0.0001). Carcass characteristics weren't affected by the Treatment. No significant differences were found between control and treated animals in health status, despite the incidence of bovine respiratory disease (BRD), digestive disorders, and animal moved to the infirmary pen, was, from a veterinary practical point of view, highly lower in treated animals. In conclusion, supplementation of fattening beef cattle diet with a pool of enzymes and beta-glucans derived from the fermentation of Aspergillus oryzae and Lactobacillus, improved growth performance and feed efficiency, but need more investigations to better clarify his role on animal welfare.
