In vitro efficacy of kaolin clay-embedded garlic powder in ruminal methane abatement in cattle

Cattle emit significant methane (CH 4 ) through ruminal digestion, making this important industry a major contributor to greenhouse gas emissions. Mitigation strategies are essential, and methane-reducing feed additives offer a sustainable solution. Methane inhibitors, including plant extracts, chemical agents, and aluminosilicate minerals have been tested. Among minerals, clay minerals are promising due to cattle's natural “geophagy”. Kaolin, an abundant clay, provides health benefits in basal diets, though raw kaolin shows limited CH 4 inhibition. Enhancing kaolin by “hosting” active ingredients improves efficacy. Garlic, a known CH 4 inhibitor, faces cost and health concerns with long-term use. We developed a halloysite-rich kaolin-garlic composite (1:1 ratio) and delivered it to the rumen. Mineralogical and microscopic analyses confirmed garlic embedding within the clay matrix. This suggests sustained availability and slow release of garlic bioactive compounds in the cattle rumen. In vitro , the composite achieved a greater than 35% CH 4 reduction ( p < 0.05) with steady kinetics and improved fermentation, advancing sustainable feed supplements for methane abatement.