The role of tannin-based products in mitigating enteric methane emissions in ruminant livestock: A review

Global greenhouse gas accumulation receives significant contributions from methane emitted by ruminant livestock, thereby exacerbating climate change. Tannin-based feed additives are being investigated by researchers as a potential means to alter rumen fermentation and reduce methanogenesis. The researchers build on previous studies on the impact of tannins on methane reduction in the digestive tract and investigate the biological mechanisms of tannins, which are coupled with the potential of animal feed sources. Tannins kill methanogenic archaea by reducing protozoa and altering volatile fatty acid composition. This simultaneously results in reduced methane emissions and improved feed and nitrogen utilization efficiency. As a result, animal production is made more efficient by the reduction of nitrogen excretion and the enhancement of protein metabolism. The use of tannins, essential oils, biochar, and probiotics together is being researched as a way to treat the diet. Yet there are still issues, such as the adverse effects of tannins on nutrition, inconsistent tannin supply across sources, and microbial adaptation over time. The effectiveness of tannins also varies and is connected to the plant source, concentration, and processing methods. Besides, scientists are developing encapsulation methods and selecting optimal feeding protocols to increase tannin effectiveness while minimizing unwanted effects. Future researchers must improve the administration techniques for tannins, develop more efficient delivery systems, and conduct a comprehensive assessment of how tannins affect rumen microbiome health and animal performance. Tannin application emerges as an ecological approach that serves sustainability in livestock management systems and helps environmental adaptation practices.