PSXI-15 Effect of different levels of dry distillers bran plus solubles on performance of Nellore bulls finished on pasture receiving high supplementation

Abstract This study was carried out to evaluate the performance of Nellore bulls finished on pasture receiving high supplementation containing different inclusion levels of dry distillers bran plus solubles (DDBS). Nellore bulls [n = 832; body weight (BW) = 390 ± 30 kg; 20 mo of age] were distributed in a randomized block design and allocated to 12 paddocks (Urochloa brizantha cv. Marandu; 7 or 8 animals/ha) measuring 10 ha (n = 6) and 8 ha (n = 6). The treatments consisted of four levels of DDBS inclusion: supplement without DDBS (S0) or containing 250 g/kg (S250), 500 g/kg (S500) or 750 g/kg (S750) of inclusion in the supplement dry matter (DM; Table 1). The DDBS used in the experiment was produced by FS Fueling Sustainability, Lucas do Rio Verde, Brazil, and had 90.8% dry matter (DM), 20.5% crude protein (CP), 38.6% neutral detergent fiber (NDF), and 6.5% ether extract (EE). The supplements were provided ad libitum daily. The finishing period lasted 103 d, from October/2023 to January/2024 (wet season). The animals were weighed fasting (16 h) on the first and last day of the experiment. The supplement DM intake (DMIs) was measured daily. All data were analyzed using the MIXED procedure of SAS. The means were compared using orthogonal polynomial contrasts (linear and quadratic). Significance was set at P ≤ 0.05 and trends were declared when 0.05 < P ≤ 0.10. A quadratic effect was observed for both final BW and average daily gain (ADG; P = 0.01 and P = 0.04, respectively). Animals kept in the S250 treatment had greater BW gain and were heavier at the end of the experimental period than the other treatments. The DMIs tended to be quadratic (kg/d, P = 0.06; and %BW, P = 0.07), with the greatest supplement intake for S250 (7.88 kg/d) and the least for S750 (7.01 kg/d). Supplement feed conversion [DMIs:average daily gain (ADG] did not differ (P ≥ 0.23) between treatments (Table 2). The DDBS inclusion also had a quadratic response in hot carcass weight (HCW; P = 0.01), where animals kept in the S250 treatment had greater carcass weight than the other treatments. However, there was no effect of including DDBS on dressing percentage (P ≥ 0.32). The inclusion of DDBS at 250 g/kg of the supplement DM improves the performance of cattle finished on pasture receiving high supplementation.