The objective of this study was to characterize the chemical composition and lipid profile of colostrum and milk of purebred Quarter Horse mares. Thirty-four (34) purebred mares were selected, which were then separated into groups according to age, birth order and lactation stage. Colostrum samples were collected in the first six hours after delivery and milk samples from the 7 th postpartum day, with intervals of 14 days until the end of lactation. The samples were refrigerated and sent to the Milk Laboratory of the University ( Laboleite — UFRN ), where they were analyzed for chemical composition. Colostrum was assessed by refractometry. The lipid profile was determined by gas chromatography through a separation of methyl esters. The data were tabulated and subjected to descriptive statistics and analysis of variance by the F-Test, and the groups were compared by the Tukey test using a significance level of 5%. There was high protein content and reduced lactose content for the colostrum of the Quarter Horse mares, differing from other breeds. The milk composition was not influenced by the mares’ age. However, variations in the lactation stage and in the birth order of the Quarter Horse mares altered the milk’s chemical composition. There is variation in the lipid composition of milk according to the lactation stage, without changing the characteristic profile of the mares’ milk or diminishing the nutritional quality of the lipid fraction.

Dur objective was to address the use of equine milk for human consumption, highlighting important compositional aspects and peculiar characteristics of this milk. Equine milk stands out for its similarity to breastmilk in compositional aspects considering the quality of the protein and lipid fractions, and due to the presence of important bioactive compounds. The high percentage of whey proteins and the structure of the protein micelles favor equine milk's digestibility, while its bioactive protein richness and the good relationships established between fatty acids highlight it as a functional food. Children who are allergic to cow's milk protein, the elderly and/or people affected by skin and gastrointestinal disorders are potential consumer of equine milk. Assays have proven the therapeutic properties of koumiss; high tolerability of equine milk by children who are intolerant to cow's milk; beneficial effects in treating atopic dermatitis and chronic diseases of the gastrointestinal tract; and potential of this milk in the prophylaxis and/or nutritional support of patients affected by several diseases. Scientific findings highlight the potential of equine milk as a beneficial food for human health, regarding both its nutritional aspects and functionalities, which could contribute to the increased demand for equine milk in global dairy market.