The aim of this study was to quantify the liquid-associated bacteria and protozoa of the rumen and to evaluate the potential of in vitro production of gases CH4 and CO2 of diets with inclusion of glycerin for sheep. Two diets were formulated with a roughage:concentrate ratio of 20:80, according to the presence or absence of glycerin: G0 - control, without glycerin; and G10 - 10% glycerin as part of the concentrate. To quantify the liquid-associated bacteria and protozoa from the rumen and production of CH4 and CO2 gases, a completely randomized design was used. The diets had no effect (P>0.05) on production and composition of liquid-associated protozoa and bacteria from the rumen of lambs. Likewise, a (P>0.05) diet effect was not observed on production of CH4 and CO2 in vitro, which presented average concentrations of 24.55mL/g MS and 51.52mL/g MS, respectively. The use of 10% glycerin did not alter production or composition of ruminal microflora, and moreover, did not negatively impact the production of CH4 and CO2 gases in vitro.
sheep; bacteria; gases; nitrogen; protozoa