Work

Influence of saponin extracts on enteric methane emission and rumen fermentation: a meta-analysis of in vitro experiments

Year: 2026

Type: review

Study designs: Systematic Review, Meta-Analysis

Abstract: Background Saponin extracts have been extensively studied as natural modifiers for the rumen. This meta-analysis aims to quantify the dose-response effects of saponin extract supplementation on rumen fermentation profiles, digestibility, microbial populations, and methane production under in vitro conditions. Results A review of peer-reviewed in vitro studies from Scopus, PubMed, and Semantic Scholar identified 36 articles with 379 datapoints and 24 saponin sources. Meta-regression analysis found quadratic responses of the levels of saponin extract with dry matter degradability (DMD), gas production, reduced methane production, protozoa abundance, and. NH 3 -N concentration. Subgroup meta-analysis revealed that the effects of saponin crude extract on in vitro rumen fermentation were source-dependent, with significant differences across most parameters. Subgroup meta-analysis demonstrated that DMD reduced by 8.0–19.1% ( P < 0.001), except Kometa lucerne which increased DMD by + 14.3% ( P < 0.001), Total VFA increased with Calendula officinalis (+ 20.5%), Knautia arvensis (+ 9.2%), and tea saponin (+ 28.8%) with increased on propionate by selected saponin sources (+ 7.7% to + 46.9%). Methane production was consistently reduced by 11–40.6%, with the greatest reduction observed for Sapindus mukorossi ( P < 0.001). Protozoa were largely unaffected except for a modest reduction (− 10.5%; P = 0.028) with ivy. Conclusions Modulating effects of saponin extracts on rumen fermentation and methane production are dependent on the origins and dose-dependent manner, suggesting diverse phytochemical characteristics of saponin from different sources. Certain sources of saponin extracts with potential methane-reducing properties were identified such as Sapindus mukorossi , Albizia lebbeck , Calendula officinalis , Chenopodium quinoa , Sapindus saporia , Saponaria officinalis , Saponaria vaccaria , and Sesbania grandiflora . However, optimized levels remain to be determined for specific saponin sources along with their specific phytochemical characteristics and specific mechanism how they modulates rumen fermentation.

Source: BMC Veterinary Research

DOI: 10.1186/s12917-026-05487-8