Development of a Methane Emission Reduction Technique for Dairy Cattle Using Soil Microorganisms: A Small-Scale Pilot Trial

Abstract

Reducing greenhouse gases, particularly methane (CH 4 ), a significant contributor to global warming, has become an urgent international priority. Ruminants, particularly dairy cattle, emit substantial amounts of methane, necessitating the development of effective mitigation strategies. Methane is primarily produced by microorganisms in the rumen and expelled into the environment through eructation. In this small-scale pilot trial, we investigated the impact of a feed additive composed of mass-cultured, inactivated soil bacteria on methane emissions in dairy cattle. The additive was administered via drinking water to Holstein heifers, functioning as an exploratory case-based approach. Within three days, a significant reduction in methane emissions and eructation frequency was observed. When dairy cattle were provided with free access to drinking water containing 10 g/L of BX-1, the number of eructations was reduced by approximately 77%, and the concentration of methane gas in exhaled air decreased by about 80%. No adverse clinical symptoms or abnormalities in blood test results were detected in cattle. These findings suggest that utilizing soil bacterial formulations as feed additives could serve as a sustainable method for reducing greenhouse gas emissions in the livestock industry, potentially contributing to global warming mitigation. Further larger-scale trials are required to confirm these preliminary results.