Vol. 9, Special Issue 1, Part N (2025)

Herbs play a vital role in reducing methane emissions from livestock. This study explores the potential of guava leaves (Psidium guajava) in mitigating methane emissions through in vitro analysis. The research examines the nutritional composition, phytochemical properties, and methane reduction potential of guava leaves. Nutritional analysis of Psidium guajava leaves revealed a dry matter content of 24.05%, crude protein at 19.17%, crude fiber at 12.81%, ether extract at 1.86%, total ash at 5.49%, and nitrogen-free extract at 60.67%. Phytochemical screening was conducted using water, methanol, and ethanol extracts to identify various bioactive compounds. The qualitative analysis confirmed the presence of alkaloids, flavonoids, tannins, phenols, saponins, carbohydrates, proteins, amino acids, phytosterols, and terpenoids across all three extracts. To assess the methane reduction potential, different concentrations of guava leaves (20, 40, 60, 80, and 100 mg) were tested in vitro. The findings indicated that higher concentrations, particularly 80 mg and 100 mg, significantly (p<0.05) reduced methane production, yielding values of 4.97 ml and 5.40 ml per 100 mg of truly digested substrate, respectively. These results highlight the potential of guava leaves as a natural strategy for mitigating methane emissions in livestock production systems.