The objective of this work was to demonstrate the first proceeding to install the semi-automated in vitro gas production technique in different laboratories. Therefore the relationship between volume of gas produced (V) and pressure generated (P) obtained manually by incubation of different substrates in fermentation bottles, should be estimated. Cynodon dactylon hay (tifton 85), Brachiaria brizanta (brachiarão), Neonotonia wightii (soja perene) and silages from four sorghum genotypes were incubated and generated 1036 values of P and V. The equation relating V and P was: V = -0.004 (s.e. 0.06) + 4.43P (s.e. 0.043) + 0.051P² (s.e. 0.007), R²= 0.99. The equation allowed the installation of the semi-automated in vitro gas production technique at the Animal Nutrition Laboratory of the Animal Science Department of the Veterinary School of UFMG.
in vitro; gas production; ruminants; semi-automated
