Inclusion of Red Osier Dogwood in High-Forage and High-Grain Diets Affected in Vitro Rumen Fermentation

Red osier dogwood (ROD) is an abundant shrub plant in Canada and other places in the world. It is rich in antioxidants such as quercetin, gallic acid and tyrosol. The objective of this study was to evaluate the effects of substituting barley silage with ROD in high-forage (HF) or high-grain (HG) diets on gas production (GP), dry matter (DM) disappearance (DMD) and fermentation characteristics in ruminal batch cultures. The study was a randomized design with 2 media pH (5.8 vs. 6.5) × 4 doses of ROD. An additional treatment of monensin and tylosin was added as a positive control for each pH level. The basic diet consisted of 60% barley silage and 40% barley grain for HF or 15% silage and 85% grain for HG diet. The barley silage was partly replaced with ROD at 0, 3, 6 or 12% in both diets (DM basis). Each diet was incubated for 24 h in culture bottles with three replicates for each treatment combination, and three runs on different days. The GP and DMD were greater (P