223 Effects of high protein DDGS in SFC or DRC-based diets on nutrient digestibility and ruminal fermentation characteristics

Abstract

Abstract The effect of high protein dried distillers grains plus solubles in steam flaked corn (SFC) or dry rolled corn (DRC)-based diets on rumen fermentation and nutrient digestion was evaluated. Six ruminally and duodenally cannulated heifers were utilized in a 6×6 Latin Square experiment using a 2×3 factorial treatment design. One factor was SFC or DRC-based diets, and the other factor was a control with no DGS (CON), regularly produced DDGS (DDGS), or High Protein DDGS (HiPro) included at 30% in the diet (DM basis). Data were analyzed using the MIXED procedure of SAS, with individual steer within period as the experimental unit. There was an interaction of apparent total tract starch digestibility (P 0.01), as including either DDGS or HiPro reduced starch digestibility in DRC-based diets and tended (P = 0.06) to reduce starch digestibility in SFC-based diets. Digestibility of starch was greater (P < 0.01) for SFC versus DRC-based diets across distillers treatments. Dry matter and OM apparent total tract digestibility was lowest (P < 0.01) for HiPro and DDGS was intermediate. There was no difference in molar acetate proportions (P > 0.43) between treatments. Dry rolled corn tended (P = 0.08) to have greater propionate proportion than SFC (44 vs 38%; respectively). Ammonia concentration was greater (P < 0.01) for DRC-based diets, and greatest for CON (P < 0.01) over DDGS and HiPro treatments. Average ruminal pH was unaffected by treatment (P > 0.16). Digestible energy (Mcal/kg) tended (P = 0.08) to be greater for CON over HiPro and DDGS. The use of HiPro did not affect apparent total tract nutrient digestibility as compared to DDGS in SFC or DRC-based diets. The use of either distillers product did result in a reduction in energy intake and digestibility, without affecting ruminal metabolic parameters.