Nutritional characterization and gas production of vegetative species with potential as feedstuffs for ruminants feeding

Objective. To evaluate the chemical composition, phenolic compounds content, and in vitro methane and gas production kinetics of seven vegetable species as potential feedstuffs for ruminants feeding. Materials and methods. Seven species were evaluated: gray oak (GO), red oak (RO), prickly poppies (PP), mesquite (MES), wattle tree (WT), white mulberry (WM) and stevia (STE). The analyses of the samples were: ether extract (EE), ash, crude protein (CP), non-structural carbohydrates (NSC), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose, cellulose, acid detergent lignin (ADL), condensed tannins (CT), total phenolic compounds (TPC), in vitro dry matter true digestibility (IVDMD); as well as under in vitro ruminal conditions, gas production (GP), methane and carbon dioxide CO2 production, N-ammonia, and volatile fatty acids (VFA). Results. The results show that WT, MES and WM foliage presented the highest content in CP, the highest digestibility's (IVDMD) were observed in PP, WM and STE. Otherwise, the lowest methane productions were generated by MES, RO and WM. Conclusions. According to the results in the chemical composition, PP, WM and STE presented the best nutritional quality since they showed the highest protein contents and an adequate digestibility. These results suggest that the use of PP would not affect the nutritional characteristics offered by good quality forage. In addition, the other species may be used as additives or supplements for feeding ruminants because of their higher protein and CT contents.