Effect of Sporadic Wet Brewer's Grain Inclusion on the Growth Performance and Carcass Performance of Heavy-Finishing Cattle

The objective of this study was to determine the effect of sporadic inclusion of wet brewer’s grains (WBG) on the growth performance and carcass performance of heavy-finishing cattle. Following backgrounding, forty-two (n=42) steer calves of Simmental-Angus genetics, weighing approximately 482kg, were utilized and finished at the Illinois State University (ISU) Farm. Animals were utilized in accordance with ISU’s Institutional Animal Care and Use Committee (IACUC) approval (Protocol #909729). Initially, calves were blocked by weight and fed one of two dietary treatments in a randomized complete block design with 7 replications per treatment. Control calves were fed a conventional finishing-diet consisting primarily of corn silage and shelled corn. Experimental groups were fed control diets with the sporadic inclusion of 8% WBG. Inclusion rates for WBG were based on product availability from a local micro-brewery and previous data showing fluctuating nutrient profiles in craft WBG. Diets were mixed on a daily basis with feed refusal collection conducted every 7d. Daily feed offered was increased in constant increments, adjusted from feed refusal and daily bunk readings. Feed was offered once daily. Calves were weighed every 28d with two-day average weights collected and used to calculate Average Daily Gain (ADG), Average Daily Feed Disappearance (ADFD), and Gain to Feed (G:F). Cattle were visually appraised by an industry procurement agent for degree of finish and transported 159km in two separate groups (97 and 124 days on feed; average final body weight of 633kg) for slaughter and processing under USDA-FSIS inspection. Following slaughter, carcass performance measurements such as hot carcass weight (HCW), ribeye area (REA), 12^th rib fat thickness (RIBF), kidney, pelvic, and heart fat percentage (KPH), and quality grade (QG) were collected. Statistical analysis was modeled in a two-way fixed ANOVA utilizing the MIXED procedure of SAS. No differences were observed in total gain (TG), ADG, and G:F across dietary treatments (P > 0.05). A decline REA was observed in calves offered WBG (P = 0.011). No differences were observed in carcass measurements of HCW, 12^th Rib Fat, KPH, QG, or Yield Grade (YG) across dietary treatments (P > 0.05). This data indicates WBG may be included sporadically at low levels in heavy-finishing cattle diets with minimal impact on growth and carcass performance. However, additional research on the cost effectiveness of including WBG at increased inclusion levels is warranted.