Mare milk is taken into account as a substitute for cow milk in case of allergy, especially in infant nutrition due to a composition similar to human milk. The aim of the work is to define some mare milk characteristics during lactation, from foaling to the 4 th month of lactation. All the parameters considered to describe fat globule dimensions vary significantly during the lactation period. Fatty acid composition generally changes within the first days of lactation and after 42-56 days, with different behavior when considering medium or higher carbon chains. The ROS-scavenging activity expresses a positive trend and reaches the zenith at day 84. Finally there is a number of correlations between fat globules dimensional parameters and fatty acid composition and between long chain unsaturated fatty acids and ROS-scavenging activity, while dimensional parameters and ROS-scavenging activity are not statistically related. Results could be useful in veterinary and human field as milk substitutes.