Effect of Corn Stover and Red Calliandra Ratios on Rumen pH, Microbial Populations, and Methane Production (In Vitro)

Abstract

This study aims to determine the effect of various ratios of corn stover (Zea mays) and Red Calliandra (Calliandra calothyrsus) on pH, Bacterial Population, Protozoa, and Methane Gas in silage as an indicator of fermentation quality. This study was conducted using a Completely Randomized Design (CRD) with four treatments: P1 (90% corn stover + 10% Red Calliandra), P2 (80 corn stover + 20% Red Calliandra), P3 (70% corn stover + 30% Red Calliandra), and P4 (60% corn stover + 40% Red Calliandra). Data were analyzed using analysis of variance (ANOVA) followed by Duncan's multiple range test. The results showed that variations in the ratio of corn stover and red Calliandra did not significantly affect the bacterial population (3.17–3.352 × 10⁹ Cell/mL) and methane production (5.55–6.141 mM) (P > 0.05). In contrast, the protozoa population significantly affected by the treatment (4.23–5.332 × 10⁵ cells/mL) and rumen pH significantly affected by the treatment (6.836–6.888) (P ≤ 0.05) with the addition of red Calliandra. All measured parameters remained within normal conditions, indicating stable rumen fermentation conditions. Although the differences in methane production and bacterial populations between treatments were not statistically significant, treatment P4 tended to show decreased methane production. These findings suggest that the combination of corn stover and red Calliandra up to a ratio of 60:40 is feasible to maintain the balance of rumen fermentation, with the potential to improve fermentation efficiency and reduce methane production. Further in vivo studies are needed to confirm these results under practical feeding conditions.