# Effects of Feeding Strategies on Gut Microbial Communities in Donkeys: A Comprehensive Narrative Review

## TL;DR

This review explores how different feeding strategies affect gut microbes in donkeys, aiming to improve their health and productivity through better nutrition.

## Contribution

The paper provides the first comprehensive framework linking dietary modifications to microbiota changes and physiological effects in donkeys.

## Key findings

- Donkeys have superior fiber digestibility compared to horses, with gut microbes providing 60–70% of metabolic energy.
- Targeted dietary interventions can modulate beneficial microbes like Prevotella and Akkermansia, potentially reducing oxidative stress and inflammation.
- Non-conventional feeds like reed silage and bamboo leaves offer sustainable alternatives for donkey nutrition.

## Abstract

This narrative review examines donkey nutrition through the lens of digestive physiology and gut microbiota interactions. Donkeys demonstrate remarkable evolutionary adaptations to harsh environments, including exceptional fiber digestibility and efficient hindgut fermentation systems where microorganisms provide 60–70% of metabolic energy. We have synthesized evidence on diverse feed resources—from traditional roughages like corn stalks and wheat straw to innovative alternatives such as reed silage, bamboo leaves, and garlic byproducts utilized in equine nutrition. Critically, the review highlights how targeted dietary interventions (protein, methionine, energy optimization) show potential to modulate beneficial microbial populations, with preliminary evidence suggesting reductions in oxidative stress and inflammation in small-scale studies, though long-term effects on growth and immunity in donkeys require further investigation with larger sample sizes and extended study durations. In addition, significant knowledge gaps remain regarding species-specific nutritional standards, necessitating further research to develop evidence-based feeding strategies for sustainable donkey production systems.

Donkeys (Equus asinus) remain nutritionally understudied despite their critical roles in agriculture across developing regions, with current feeding practices inappropriately extrapolating horse standards without accounting for species-specific digestive physiology. No comprehensive synthesis has integrated how dietary modifications systematically alter gut microbial communities to drive measurable health outcomes in donkeys, preventing development of evidence-based feeding strategies. This review critically synthesizes current evidence on donkey nutritional requirements and gut microbiota dynamics to establish mechanistic frameworks for optimizing health and productivity. Donkeys exhibit remarkable adaptations including 30% superior fiber digestibility versus horses and specialized hindgut fermentation where microbiota provide 60–70% of metabolic energy. Targeted nutritional interventions—protein supplementation (12.52%), methionine supplementation (5–15 g/day), and optimized energy levels (10.49 MJ/kg)—have shown preliminary evidence of modulating beneficial microbial populations (Prevotella, Ruminococcus, Akkermansia, Bacteroides), with short-term studies (typically 30–60 days, n < 10 animals) indicating potential reducing oxidative stress (20–40%), decreasing inflammatory cytokines (30–50%), and improving growth performance (15–25%). However, these findings require validation through larger-scale, longer-term studies to establish sustainable effects and broader applicability. Non-conventional feeds including reed silage, bamboo leaves, and garlic byproducts offer sustainable alternatives. This narrative review uniquely establishes mechanistic pathways linking dietary modifications to microbiota changes and downstream physiological effects, providing the first comprehensive framework integrating digestive physiology, microbiota ecology, and nutritional interventions specifically for donkeys to support evidence-based, sustainable feeding strategies.