Tree Legumes of Temperate Climate: Effect on the Mitigation of Enteric Methane and Ruminal Fermentation In Vitro

The effect of legumes adapted to a temperate climate on gas production kinetics, enteric methane, and rumen fermentation in vitro was evaluated. The species studied were Acacia dealbatha, Acacia melanoxylon, Albizzia lopantha, Lupinus pubescens, Inga insignes, Senna multiglandulosa and Tecoma stans. The effective degradation of the dry matter was estimated, the in vitro gas production was measured up to 120 hours of incubation, and the production of enteric methane, VFAs, and ammonia were measured at 24 hours. Dry matter, organic matter, ash, crude protein, neutral detergent fiber, acid detergent fiber, and acid detergent lignin were evaluated. The content of total phenols and condensed tannins was quantified. To determine digestibility, the samples were incubated for up to 120 hours. I. insignes presented a higher dry matter content and a high crude protein content. L. pubescens presented low dry matter digestibility. The neutral detergent fiber content was higher in I. insignes and with a higher value in dry matter digestibility and lower content of total phenols and condensed tannins. While S. multiglandulosa showed low detergent acid fiber content. The acid detergent lignin value was higher in I. insignes and lower in L. pubescens. In vitro gas and enteric methane production was higher in L. pubescens. propionic acid and ammonia they were higher in S. multiglandulosa. It is concluded that the amount of secondary compounds affects methane production, compromises digestibility and rumen kinetics of the legumes studied.