372 Evaluation of the value of fiber in distillers grains plus solubles on performance of finishing cattle

A finishing experiment was conducted to determine the value of the fiber in distillers grains plus solubles for cattle. The experiment utilized 800 crossbred yearling steers (initial BW = 415 kg; SD = 24 kg) fed in 100 pens (8 steers/pen and one of 5 treatments (n = 20 pens/treatment). Cattle were split into 4 blocks by starting blocks each week for 4 consecutive weeks. Cattle were limit fed 5 d before starting experiment and were weighed on Day 0 and 1 for an accurate initial BW. The 5 treatments consisted of a corn control diet (CON), 20 (20MDGS) or 40% (40MDGS) modified distillers grains plus solubles (MDGS), plus 2 diets containing corn germ meal and corn bran balanced to equal the fiber content of the 2 MDGS diets (20FIB and 40FIB). Performance data were based on 134 d (blocks 1, 2, 3) or 148 d (block 4) and carcass data were collected at slaughter and following a 48 h chill. Statistics were completed using the mixed procedure of SAS with pen as the experimental unit. Initial BW (P = 0.63) was not influenced by treatment. Intakes were impacted by treatment (P < 0.01) and DMI increased quadratically (P < 0.01) as MDGS increased with steers fed 20MDGS having the greatest DMI. Steers fed 40MDGS or 40FIB had similar DMI (P = 0.76), whereas steers fed 20MDGS consumed more (P < 0.01) than steers fed 20FIB. When 20FIB and 40FIB were fed, DMI increased linearly (P = 0.01) relative to CON. Dietary treatment impacted ADG (P < 0.01) with ADG increasing quadratically (P = 0.02) as MDGS inclusion increased, and equal ADG between 20MDGS and 40MDGS (P = 0.96). Feeding 20FIB and 40FIB slightly reduced ADG but not statistically (P > 0.14) compared to CON. As a result of increased ADG, G:F increased linearly (P < 0.01) for steers fed MDGS. When steers were fed 20FIB or 40FIB, G:F decreased linearly (P < 0.01) due to an increase in DMI and numerical decrease in ADG compared to CON. The feeding value (change in G:F due to MDGS inclusion) of MDGS was 107 to 108% of corn that was replaced in CON. The isolated fiber component does not give equal performance to feeding MDGS and G:F was slightly reduced if only the fiber components replaced corn.