Vol. 9, Issue 2, Part B (2025)

This study aims to evaluate the effect of guava leaf methanolic extract on in vitro rumen gas production, pH, NH₃-N, and VFA concentration. Guava leaves were harvested from the University of Putra Malaysia farms and used to prepare guava leaf methanolic extract (GLE). The experimental diets were Ctrl, T200, T300, and T600, which included 0, 200, 300, and 600 mg GLE\ Kg of diet, respectively. Six replicates of 200 mg diet samples from each treatment were put in 100 ml syringes with 20 ml of incubation liquid and incubated at 38^oC for 24 hours. Gas production was recorded at times 2, 4, 6, 8, 10, 12, and 24 hrs. of incubation, while the pH, NH₃-N, and VFAs were determined in the rumen liquor at the end of the incubation. Gas production significantly (p<0.05) reduced in 2, 4, and 24 hrs of incubation and gas production rate. No significant differences were recorded in the total VFA’s, Acetic, Propionic, acetic/ propionic ratio, Butyric, and the pH of rumen liquor. In contrast, a significant (p<0.05) increase in the level of NH₃-N was noted in T300 compared to other treatments. With good availability of NH₃-N and no effect on different characteristics of the rumen, using 300 mg of guava leaf methanolic extract per Kg of sheep diet was the best result.