# Effects of Quinoa Secondary Metabolites on In Vitro Fermentation and Gas Production

## TL;DR

This study explores how quinoa's natural compounds can reduce methane emissions from livestock digestion, offering a potential solution to lower agricultural greenhouse gases.

## Contribution

The study identifies quinoa varieties with high secondary metabolites that significantly reduce methane production in vitro.

## Key findings

- Quinoa lines 770 and 811 showed the lowest methane production in vitro.
- Methane yield was negatively correlated with tannin, saponin, and flavonoid content.
- Feeding quinoa silage to ruminants may reduce greenhouse gas emissions.

## Abstract

Agricultural greenhouse gas emissions constitute a significant portion of global emissions, with methane produced by rumen fermentation in ruminant livestock being particularly notable. This study investigates the feeding effects of the emerging forage crop quinoa, moving away from traditional additive-based rumen regulation methods. Instead, it utilizes secondary metabolites abundant in quinoa, such as saponins and tannins, to modulate rumen activity. The research verifies the impact of quinoa on greenhouse gas emissions and identifies two quinoa varieties suitable for use as forage among several tested. These findings offer new insights into the exploration of novel forages and provide methods for reducing greenhouse gas emissions in livestock production.

Livestock methane emissions are a significant source of greenhouse gases. The aim of this study was to investigate the secondary metabolites of different strains of silage quinoa and their impact on methane emissions from livestock farming. In this study, we evaluated the chemical composition, fermentation quality, secondary metabolite content, and in vitro gas production of eight quinoa lines, 093, 137, 231, 238, 565, 666, 770, and 811, grown in saline and alkaline areas of the Yellow River Delta. The results showed that crude protein, EE, and crude ash content ranged from 8.84% to 10.69%, 1.98% to 2.38%, and 17.00% to 23.14%, respectively. The acidic and neutral detergent fiber content of these eight quinoa varieties ranged from 49.31% to 61.91% and 33.29% to 37.31%, respectively. Line 093 had the highest total saponin content, while Line 231 exhibited the highest flavonoid content. Methane yield was significantly and negatively correlated with tannin, saponin, and flavonoid content, whereas carbon dioxide yield showed a positive correlation with saponin and flavonoid content. Among all lines, 770 and 811 demonstrated the lowest methane production, indicating strong in vitro inhibition of methanogenesis. These findings suggest that feeding quinoa silage to ruminants has the potential to reduce greenhouse gas emissions.