Evaluation of RUP Content of NexPro Dried Distillers Grains plus Solubles in Corn Silage Based Growing Calf Diets

An 85 d growing study was conducted to evaluate the effect of supplementing NexPro, a high-protein dried distillers grains plus solubles from the FluidQuip MSC post-fermentation separation process, in a cornsilage based diet and to determine the RUP content of NexPro and performance of growing cattle fed this feedstuff. Crossbred steers (n = 120, initial BW = 250 ± 24kg) were individually fed using the Calan gate system and assigned randomly to treatment. Treatments were arranged as a 3×4 + 1 factorial with test protein type (Soybean meal [SBM]; non-enzymatically browned soybean meal [SoyPass]; high-protein DDGS [NexPro]) and supplemental protein concentration (4.5, 9.0, 13.5, or 18.0% diet DM) as factors. Crude protein content of NexPro, SoyPass and SBM were 51.4, 48.8, and 52.4%, respectively. All treatments were compared to a control with 0.0% inclusion of test protein and a corn-based, urea-containing RDP supplement. Diets contained 80% corn silage with test protein replacing RDP supplement as inclusion increased. Data were analyzed using the GLIMMIX procedure as a completely randomized design with individual animal as experimental unit. By design, RUP intake increased linearly (P < 0.01) across all treatments. Ending BW responded linearly (P < 0.01) for all treatments. Steers fed SoyPass or NexPro had no change (P > 0.18) in DMI, while SBM had a tendency for a quadratic increase (P = 0.07). Gains increased linearly (P < 0.01) for SoyPass and increased quadratically (P = 0.01) for SBM and NexPro. This resulted in linear increases (P < 0.01) in feed efficiency with increasing inclusions of test proteins. In situ mobile bag technique was used to determine RUP content of the supplemental proteins. The RUP content as a % of CP for NexPro, SoyPass and SBM were 50, 74, and 22%, respectively. Feeding DDGS from the FluidQuip process improved calf performance by increasing DMI, ADG, and efficiency in growing diets.