Effects of Feeding Two Levels of a Pelleted 30 Percent Pea Starch and 70 Percent Dry Distillers Grain Feed in Feedlot Finishing Diets on Animal Performance and Carcass Characteristics

One hundred seven Angus and Angus-cross steers were used in a feedlot finishing study to evaluate feeding 2 dietary levels of a combined pea starch (PS), corn dry distillers grains (DDGS) pelleted feestuff. Steers were blocked by initial BW (average 456 ± 2.11 kg) and sorted into 4 weight blocks. Within block, cattle were assigned randomly and sorted into 1 of 12 pens. Pens were assigned randomly to 1 of 3 dietary treatments. Air-fractionated PS and DDGS were combined at a rate of 30% PS and 70% DDGS into a small diameter feed pellet (PS-DDGS). The 3 treatment diets were: control (Con), 15% PS-DDGS pellet and 30% PS-DDGS pellet (15PS-DDGS and 30PS-DDGS). The Con diet included 64% dry rolled corn, 14% Straw, 20% DDGS (no PS) and 2% vitamin and mineral supplement (VMS). The DDGS was from the same source used in the PS-DDGS pellet. The 15PS-DDGS diet included 69% rolled corn, 15% PS-DDGS, 14% straw, and 2% VMS. The 30PS-DDGS diet included 54% rolled corn, 30% PS-DDGS, 14% straw, and 2% VMS. The 2 PS-DDGS diets contained no additional DDGS besides what was contained in the pellets. All diets were similar in energy at 1.30 Mcal/kg NEg. Crude protein was 13.7, 11.8, and 14.2% for Con, 15 and 30PS-DDGS diets, respectively. Steers were weighed every 28 d and at the time of marketing. Steers were fed an average of 101 d. Hot carcass weights were recorded on the day of harvest. Carcass 12th rib fat thickness (BF), longissimus muscle area (LMA), and U.S. Department of Agriculture marbling score and yield grades (YG) were recorded following a 24-h chill. Initial and final BW were similar (P ≥ 0.35) for Con, 15- and 30PS-DDGS treatments. Although dry matter intake was similar (P = 0.33) across all treatments, the 30PS-DDGS-fed cattle tended (P = 0.10) to have higher G:F than cattle fed the 15PS-DDGS, and greater ADG than cattle on the 15PS-DDGS and Con treatments (P = 0.10). Hot carcass weight, YG, LMA and marbling score were similar (P ≥ 0.23) for Con, 15 and 30PS-DDGS treatments. Final BF was similar for 30PS-DDGS and Con, but greater than 15PS-DDGS (P = 0.02). The PS-DDGS pellet effectively replaced DDGS and some corn in feedlot finishing diets. The 30PS-DDGS inclusion level improved animal performance and feed efficiency compared to the 15PS-DDGS inclusion level.