Abstract:
The objective of this work was to evaluate the effect of the addition of the methanolic extract of Urochloa humidicola at four different concentrations (0, 75, 150, and 250 g L-1) on the in vitro rumen fermentation of Urochloa brizantha. The following variables were evaluated by the in vitro gas production technique: kinetic parameters; rumen degradation of dry matter; and production and concentration of the methane and carbon dioxide gases and of the acetate, propionate, and butyrate short-chain fatty acids. The addition of the methanolic extract reduces the production of gases generated from the degradation of non-fibrous carbohydrates (fraction A) in 9.55, 6.67, and 13.33%, respectively, at the concentrations of 75, 150, and 250 g L-1, compared with the control group, but it negatively affects the degradation of the dry matter of U. brizantha at the concentrations of 150 and 250 g L-1. The extract shows negative quadratic effect on gas production during 12 and 24 hours of U. brizantha incubation. The extract of U. humidicola reduces methane production and increases short-chain fatty acid production at the concentrations of 75, 150, and 250 g L-1.
Index terms:
Urochloa humidicola; methane mitigation; rumen metabolism; secondary plant metabolites