In Vitro Evaluation of Ruminal Fermentation and Methane Production in Response to the Addition of Modified Nano-Bentonite with or Without to a Forage-Based Diet.

Modified nano-clays, alone or combined with probiotics, may offer a novel and sustainable approach to improve ruminal fermentation and mitigate CH emissions in high-fiber diets. This study evaluated the properties and effects of modified nano-bentonite (MNB), with or without yeast (), compared to natural bentonite (NB) and monensin, using the in vitro gas production (GP) technique. The substrate used was a basal diet composed primarily of forage ( clover) in a 70:30 forage-to-concentrate ratio. The treatments were a control group receiving the basal diet without additives; a monensin-added diet containing 40 mg/kg of dry matter (DM); a yeast-added diet with at 2 × 10 CFU/g of DM; a NB clay-added diet at 5 g/kg of DM; and MNB diets added at two levels (0.5 g/kg of DM (MNB) and 1 g/kg of DM (MNB)), with or without . MNB showed a smaller particle size and improved properties, such as higher conductivity, surface area, and cation exchange capacity, than NB. Sulfur and related functional groups were detected only in MNB. No differences were observed in total GP, while both the monensin diet and the MNB-with-yeast diet significantly reduced CH emissions compared to the control ( < 0.05). The MNB-without-yeast combination significantly ( < 0.05) reduced hemicellulose degradation, as well as total protozoal counts, including and spp. ( < 0.05), compared to the control. Ammonia levels did not differ significantly among treatments, while NB and MNB diets tended to have ( = 0.063) the highest short-chain fatty acid (SCFA) concentrations. These findings suggest the potential modulatory effects of yeast and MNB on rumen fermentation dynamics and CH mitigation.