Reduction of Methane Emission in Ruminants Via Modern Feeding

Abstract

Methane emissions contribute to greenhouse gas accumulation from ruminant animals and are documented as a significant challenge for sustainable livestock production because it decreases the effectiveness of feed utilization. The ruminal fermentation process helps to maintain rumen function with the loss of 2–12% of dietary gross energy and by converting the hydrogen and carbon dioxide into methane due to the methanogenic archaea. The developing feeding strategies due to the continuous change in the climate focused to diminish methane emissions without disturbing the animal performance. This review examines approaches used in ruminants and discusses the mechanisms of action, effectiveness, and practical applications for mitigating enteric methane production.  The lipid supplementation, nitrate incorporation, tannin-containing feeds, essential oils, ionophores, seaweed-based additives, and 3-nitrooxypropanol are evaluated in this study with the feed processing techniques and precision feeding systems. Dietary lipids at 15–25% are reported to decrease methane emissions, while nitrate can reduce emissions by 20–40%. The moderate reductions were reported with the tannins and other plant-derived compounds, while the red seaweed Asparagopsis taxiformis recorded high mitigation potential with an 80% reduction in some studies. Similarly, 3-NOP demonstrated considerable methane suppression without major adverse effects on animal productivity. The current study's evidence suggested that the combination of multiple mitigation approaches can give more sustained reductions than depending on a single intervention. Therefore, there is a need for careful attention to the important factors such as feed cost, animal health, product quality, regulatory approval, and producer acceptance. The integrated nutritional management can provide the pathway for lowering methane emissions and enhancing the sustainability of ruminant production systems.