Equine Contribution in Methane Emission and Its Mitigation Strategies.

This research investigates the contribution of horses to methane gas emissions, and proposes strategies to mitigate these emissions, thereby supporting sustainability efforts.

Introduction

• The paper begins by emphasizing the importance of greenhouse gas emission mitigation for maintaining the earth’s sustainability.
• It specifically targets methane, a greenhouse gas that is produced by nonruminant herbivores, such as horses, through a biological process known as hindgut fermentation. This means the horses break down undigested food in their large intestines which produce methane.

Methane Production in Horses

• Several factors influence methane production in horses. These include their diet, feeding frequency, the season, their genome (genetic makeup), and the population of protozoa (single-celled organisms) in their digestive system.
• The paper identifies four classes (clades) of organisms – Methanomicrobiales, Methanosarcinales, Methanobacteriales, and Methanoplasmatales – that are often found in horses and contribute to methane production.
• Among these, Methanocorpusculum labreanum is common in hindgut fermenters like horses and termites.

Factors Reducing Methane Output in Horses

• Naturally, processes like acetogenesis (the creation of acetate, a potential alternative to methane) and the interactions between the horse’s gut and immune system reduce methane output.

Methane Mitigation Strategies

• The research discusses several potential strategies for further reducing methane output in horses. These include the use of biochar (a type of charcoal), increase in acetogens (organisms that produce acetate), the inclusion of fiber enzymes and plant extracts in the horses’ diet, and the recycling of fecal energy through anaerobic gas fermentation.
• Notably, these strategies not only aim to reduce methane emissions but also to increase the energy that horses can derive from their feed intake.
• The suggested mitigation strategies could also be applicable to ruminant animals (those that chew the cud), potentially providing a wider scope for reducing overall methane emissions from livestock.