PSXI-10 Effects of feeding doses of enzyme complex and corn ethanol coproduct on performance and carcass traits of finishing beef cattle

The use of enzyme complex and the inclusion of corn ethanol co-products are strategies that can increase feed efficiency and carcass weight of feedlot beef cattle. Crossbred bulls (n = 389) were assigned to a randomized completed block design, according to their initial shrunk body weight (BW; 314 ± 40 kg; 10 pen/treatment). The treatment arrangement was a 2 × 3 factorial, with Factor 1 defined by the inclusion of corn dried bran/fiber plus distillers solubles (15 or 45% of DFS; FS Ouro from FS Bioenergy) and factor 2 defined by the increasing doses of multicarbohydrase complex (Rovabio Advance from Adisseo Company; 0, 0.75 or 1.0 g for every 10 kg of diet DM)). The diets contained 8.5% sugar cane bagasse, 44 or 73% ground flint corn, 15 or 45% DFS, 0.5 or 1.5% urea and 2% mineral mix plus monensin (30 ppm in the diet) with the respective enzyme complex doses. On d -1 and 122, individual BW were recorded after a 16-h of fasting (feed and water). The dry matter (DM) intake (DMI) was determined by the difference of feed offer and orts samples after dried at 105°C for 24 h to determine DM. The pen average daily gain (ADG) and DMI were used to calculate feed efficiency (ADG/DMI). On d 122, subcutaneous fat thickness (FT) and the rib eye area (REA) were obtained by means of an ultrasound image, and hot carcass weight (HCW) was obtained upon slaughter on the next day. Data were analyzed using the MIXED procedure of SAS. There was no interaction between the inclusion of DFS and enzyme doses for the variables evaluated (P > 0.05). The use of enzyme complex had no effect on cattle DMI, ADG and FE (P > 0.05). No effects of DFS levels were observed on daily DMI (P ≥ 0.45) or final BW (P ≥ 0.33). Nonetheless, cattle fed 45% DFS had greater ADG (1.37 vs. 1.28 kg; P = 0.02) and FE (153 vs. 145 g/ kg; P = 0.03) than cattle fed 15% DFS. There was no effect of the inclusion of DFS or the doses of the enzyme complex on the carcass parameters evaluated. In summary, including 45% DFS in finishing diets improved feedlot cattle performance compared with 15%. The use of the enzyme complex did not affect animal performance.