Impact of Corn Oil Removal from Modified Distillers Grains Plus Solubles and Supplemental Corn Oil on Finishing Cattle Performance

The effects of added corn oil in distillers grains plus solubles on finishing cattle performance was evaluated utilizing 320 steers (initial BW = 413 kg; SD = 25 kg) fed in 32 pens (10 steers / pen and one of 4 treatments (n = 8 pens / treatment). Cattle were limit fed 5 d prior to starting and weighed on d 0 and 1 for initial BW. The four treatments consisted of a corn control diet (CON), 40% deoiled modified distillers grains plus solubles (Deoiled MDGS), 38% deoiled modified distillers grains plus solubles plus 2% corn oil (MDGS+Oil), and 40% full fat modified distillers grains plus solubles (Full Fat MDGS). The deoiled MDGS product contained 8.9% fat while the full fat MDGS product was 11.6% fat. All MDGS and corn oil were sourced from the same plant. Performance data were based on 134 d and carcass data were collected at slaughter and following a 48-h chill. Data were analyzed using the mixed procedure of SAS with pen as the experimental unit and treatments were compared using a protected F-test. Intakes were impacted by treatment (P < 0.01) with steers fed Deoiled MDGS having the greatest DMI (P < 0.05) and steers fed CON, MDGS+Oil, and Full Fat MDGS having lower but similar DMI (P > 0.15). Dietary treatment had a tendency to impact ADG (P = 0.06) and HCW with the three modified distillers treatments all having similar gains (P > 0.23) but Deoiled MDGS and MDGS+Oil were greater than CON (P < 0.04) while Full Fat MDGS was similar to CON (P = 0.14). As a result of increased ADG, G:F was improved (P < 0.03) for cattle fed treatments containing MDGS compared to CON. The greatest G:F was observed for cattle fed MDGS+Oil (0.165; P < 0.05) while Full Fat MDGS was similar to MDGS+Oil (0.159 and 0.165, respectively; P = 0.15) and Deoiled MDGS (0.157; P = 0.55). Marbling score (P = 0.64) and LM area (P = 0.52) were not impacted by dietary treatment. Fat thickness followed ADG with the MDGS treatments having a greater fat thickness than CON (P < 0.02). Feeding MDGS improved G:F by 6 to 11% compared to feeding corn; however, G:F was increased 4.9% when 2% dietary oil was added back to deoiled MDGS whereas only a 1.2% increase in G:F was observed for Full Fat MDGS compared to deoiled MDGS.