A Comprehensive Review on Equine Milk: Composition, Functional Properties, Technological Applications, and Future Perspectives

Mare and donkey milk have attracted scientific and commercial interest due to their distinctive biochemical composition and functional potential as nutritional sources. Their compositional similarity to human milk—particularly regarding lactose content, protein profile, and mineral balance—makes them relevant alternatives for individuals with bovine milk intolerance and suitable candidates for nutraceutical and biomedical research. This systematic review provides an overview of the physicochemical properties of the milk of these species, examining the influence of breed, diet, and lactation stage on yield and composition. Particular attention is given to bioactive compounds, including lysozyme, lactoferrin, and immunoglobulins, which have been associated with antimicrobial, anti-inflammatory, and immunomodulatory activities. The review also discusses technological processing methods, such as fermentation, pasteurization, and lyophilization, and their effects on functional and therapeutic properties. Finally, current challenges in production and research are addressed, including the need for standardized protocols, sustainable management strategies, and further investigation into the health-related properties of mare and donkey milk.