In vitro gas and methane production of two mixed rations influenced by three different cultures of Saccharomyces cerevisiae

The current study aimed to evaluate if the effect of Saccharomyces cerevisiae (SC) on in vitro fermentation can be affected with the crude protein (CP) content of the ration. Three commercial SC cultures of Biocell F53 (R), Procreatin 7 (R), and Biosaf SC47 (R) were evaluated at 0 (SC0), 2 (SC2), and 4 (SC4) mg/g dry matter (DM) of substrate. Two rations with 13% (low crude protein [LCP]) and 16% CP (high crude protein [HCP]) were used as substrates. Rumen gas (gas production [GP]) and methane (CH4) productions were recorded. The HCP ration had increased (P = .05) asymptotic GP, CH4 production, and fermentation parameters. Biocell F53 (R) and Biosaf SC47 (R) increased the asymptotic GP (P < .05) in HCP and LCP rations with better effect for the dose of 2 mg/g DM substrate HCP (P < .05) and dose of 4 mg yeast/g DM substrate with the LCP ration. The highest CH4 production was observed (P < .05) with Procreatin 7 (R). It could be concluded that HCP ration improved GP than LCP ration. Moreover, addition of Biocell F53 (R) and Biosaf SC47 (R) at rate of 2 mg/g DM improved fermentation kinetics and nutrients degradability.