Development and evaluation of an in vitro procedure to assess enteric methane production

Livestock production systems are estimated to emit 14.5% of the global anthropogenic greenhouse gases (GHGs). Methane (CH4) emissions from enteric fermentation of cows is the main source of GHGs emissions from the livestock sector, contributing for the 44% of the total. Nowadays research is focusing on finding technical solutions to mitigate these emissions. One strategy is the addition of natural additives in the cows diet, especially since the use of antibiotics as feed additives was banned in EU. In vitro fermentation trials are a useful strategy to simulate a ruminal digestion process and to test the effect of several compounds in reducing enteric CH4 production. The aim of this study was to develop a method to assess an in vitro enteric fermentation process. An automatic system (Ankom RF Gas Production System) for gas production (GP) measurement was used. The set-up protocol was validated by investigating the effect of two feed additives on CH4 and volatile fatty acids (VFAs) production. The developed procedure has shown to be appropriate to perform enteric fermentation trials. The additives did not show any significant (p>0.05) effect on the tested parameters. Keywords-ruminal fermentation, gas emissions, additives.