Regression equation to estimate volume of ruminal gases and correlation between chemical composition and fermentation parameters

Abstract

The objective was to determine the regression equation to estimate the volume of gases for the implementation of the semi-automatic technique of in vitro gas production and to evaluate the correlation between ruminal fermentation parameters and chemical composition of tropical forages. The species evaluated were Urochloa brizanthacv. MG-5, Andropogon gayanus, Urochloa humidicolaand Digitaria umfolozi. Forages were evaluated for chemical and kinetic composition of ruminal fermentation using the semi-automatic in vitro gas production technique. The minimum gas pressure obtained was 0.09 psi, with the maximum recorded pressure being 4.8 psi, the minimum registered gas volume was 0.30 ml and the maximum 20 ml. The linear equation is the one that best predicts gas volume data in relation to pressure, as it has an R2 value and a correlation ranging from 0.94 to 1.00, respectively). The increase in dry matter, organic matter, crude protein and lignin content reduces the total volume of gases produced. The chemical-bromatological composition correlates with some ruminal fermentation parameters, reflected in the degradation kinetics of forages.

Keywords

• degradability
• digestibility
• forage
• grass
• gas production
• semi-automatic technique