193 Impact of Corn Silage Moisture And/Or Kernel Processing at Harvest on Finishing Steer Growth Performance, Efficiency of Dietary Net Energy Utilization and Carcass Traits

Abstract

Abstract Steers (n = 192; initial shrunk BW = 446 ± 28.3 kgs) were used in a 112-d finishing experiment Treatments were arranged in a 2 x 2 factorial (24 pens total; 8 steers/pen) to evaluate corn silage moisture [1/2 to 2/3 milk line (ML) and black line (BL)] and kernel processing at harvest on finishing steer growth performance and carcass traits. Steers were blocked by batch fraction (n = 6) and pen as the experimental unit. The model included the effects of harvest time, processing, and their interaction. Block was included as a random factor. No harvest time x KP interaction was detected (P ≥ 0.28) for any growth performance related parameters. No Harvest time × KP interaction was detected (P ≥ 0.26) for any parameters related to the efficiency of dietary NE utilization. Comparative NEm for harvest time indicates that delayed harvest enhanced corn silage NEm by 6% and KP decreased apparent NEm value of corn silage by 9% compared with current feeding standards. No harvest time × KP interaction (P ≥ 0.08) was detected for any carcass traits except the distribution of USDA Prime carcasses (P = 0.04). Steers from ML/KP- had the fewer (P = 0.05) USDA Prime carcasses compared with ML/KP+, BL/KP-, and BL/KP+. Harvest time (P ≥ 0.07) and KP (P ≥ 0.07) had no appreciable influence on any carcass trait parameters. These data indicate that corn silage harvest can be delayed without detriment to growth performance and kernel processing does not enhance the apparent feeding value of corn silage when corn silage is fed as the sole roughage component of a feedlot finishing diet (i.e., 20% inclusion DM basis).