Comparative Analysis of Ruminant and Equine Milk: Quality Assessment and Potential Benefits for Human Nutrition

Milk is a highly nutritious food and a cornerstone of the human diet, supplying not only essential macronutrients but also a wide range of bioactive compounds with important functional and health-promoting properties. This study presents the first comparative analysis of ruminant (cow, goat, sheep) and equine (mare, jenny) milk samples collected in Serbia, with emphasis on their physicochemical properties, protein profile, redox characteristics, and nutritional potential. Ruminant milk had significantly higher protein concentrations, with cow and sheep milk containing the highest levels of protein. Two equine milks demonstrated a distinctive whey-to-casein protein ratio to ruminants, and a higher content of active sulfhydryl groups, correlating with improved digestibility and functional properties. Antioxidant potential was determined using spectrophotometric and electrochemical methods, confirming superior redox potential in mare’s milk, followed by jenny’s and sheep’s milk. Nutritional properties of milk separated by Principal Component Analysis highlighted species-specific profiles of equine milks as a promising alternative for individuals with an allergy to cow’s milk protein, offering enhanced antioxidant protection, bioactive compounds, and digestibility. These results support the potential of equine milk as a functional food with added value in human nutrition.