Effect of Mid-Term Dietary Administration of the Caesalpinia coriaria Extract on the Sustainable Mitigation of Equine Fecal Methane, Carbon Monoxide and Hydrogen Sulfide Production.
Authors: Acosta Jorge Alfonso Diego, Elghandour Mona M M Y, Mariezcurrena-Berasain Maria D, Adegbeye Moyosore J, Fajemisin Adebowale N, Pliego Alberto Barbabosa, Salem Abdelfattah Z M
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Researchers investigated whether Caesalpinia coriaria extract—a tannin-rich plant supplement—could reduce problematic gases in equine faeces when administered orally over 30 days. Horses received either no extract, 60 mL or 120 mL daily mixed into feed, and their faecal samples were subsequently tested in vitro with varying extract concentrations to measure methane, hydrogen sulphide and carbon monoxide production. Somewhat counterintuitively, horses receiving CC extract actually produced more methane than controls (P = 0.0457), though the extract showed promise for reducing hydrogen sulphide—particularly at the 1.8 mL/g dry matter dose, which produced significantly lower levels than untreated samples. The authors recommend a practical protocol of 60 mL daily oral supplementation combined with 0.6 mL/g dry matter of extract in the diet as an optimal balance for mitigating greenhouse gas emissions, despite the increased methane findings. These results suggest that whilst CC extract may not be the silver bullet for methane reduction some hoped for, its hydrogen sulphide suppression properties warrant further investigation in commercial settings, especially for stabled horses where air quality and respiratory health are concerns.
Read the full abstract on PubMed
Practical Takeaways
- •Caesalpinia coriaria extract supplementation at 60 mL/day may help reduce hydrogen sulfide production in equine feces, which could reduce stable odor and respiratory irritation
- •The extract paradoxically increased methane production in this in vitro model, suggesting field validation is needed before implementing as a methane mitigation strategy
- •This is preliminary laboratory work; on-farm trials are necessary before recommending dietary changes to horse owners seeking to reduce environmental gas emissions
Key Findings
- •Fecal samples from horses receiving no Caesalpinia coriaria extract produced the lowest methane (P = 0.0014), while extract-treated feces produced significantly more methane
- •All Caesalpinia coriaria doses linearly increased methane production compared to control (P = 0.0457)
- •Hydrogen sulfide production was highest in feces from horses given 60 mL/day extract, with fecal type × dose interaction showing 1.8 mL/g DM extract produced the lowest H₂S
- •The authors recommend 60 mL/day Caesalpinia coriaria extract with or without 0.6 mL/g DM extract for sustainable mitigation of greenhouse gas emissions in horses