Methane production in an in vitro rumen incubation is reduced when leaves from Mimosa pigra are the protein source compared with Gliricidia sepium.
The aim of this study was to evaluate the effect of potassium nitrate or urea on methane production from Mimosa and Gliricidia leaves in an in vitro incubation system with molasses as the energy source. The incubation was for 24 h with measurements of total gas and methane concentration over incubation periods (separate experiments) of 6, 12, 18 and 24 hours and determination of residual unfermented substrate at the end of each experimental period. Gas production, percentage methane in the gas and methane produced per unit DM solubilised for each incubation were lower with potassium nitrate than with urea. Methane production per unit DM solubilised was less with Mimosa than with Gliricidia in incubations over 18 and 24 h, but did not differ between the two kinds of leaves for the 6 h and 12 h incubations.