The role of maternal behavior, as biological feature of mares, in the course of reservation of a fruit, and for the first time days of its post-natal development is established. It is for the first time defined that foals at the birth, had, at least, three congenital food reflexes. I.e. unconditional and reflex (instinctive), developed in the course of evolution of the sort Eguus. By long-term researches of authors there established that congenital reflexes (instincts) of foals, play more significant role, than the acquired (obligate) behavior, for the first time hours of post-natal development of an organism. All observations made exactly during the first hours after the delivery specify that foals at the birth already had at least three congenital reflexes: The first is that the power supply is in some part of a mothers' body at height of the extended head because first "pokes" forward nasal part of a muzzle in search of an udder, are carried out in the majority by directly extended head, or from below up. Second, not less essential congenital reflex in the biological plan is that the newborn foal from first minutes of birth, searching a dairy nipples makes along the lower part of the case, from forward feet to back across. In this part of a trunk there were mammary glands of their far ancestors. The third congenital reflex of a newborn foal is an ability of an organism to consume a significant amount of milk, in such a short time because for mares milk flow occurs in batches. The newborn has no certain sequence searching most likely the smell of warm colostrum defines ways of search. If not to consider the efforts of mare caused by a maternal instinct in simplification of search of an udder the first two congenital reflexes are the most important in aspiration, and at times and independent finding of an udder. The interrelation (correlation) is established between all four signs which characterize maternal instinct and growth rate and the developments of posterity promoting a survival (safety) of young growth. The greatest correlation concerning behavioral signs is noted between a maternal instinct of a licking and behavior of a foal expressed in the general duration of sucking an udder. It is quite clear, the dependence of a milk yield of the mare with a live mass of foal points to rapid growth and development. Interdependence of signs is expressed in close interrelation, degree of correlation fluctuates within 0,534-0,711, at high degree of reliability (P ≥ 0,99), the exception makes only a link between duration of a sucking and a milkiness (0,382 ± 0,288). The authors have established the feasibility of leading selection in the expression of the maternal instinct (behavior), to improve the survival of foals in pasture horse breeding. Efficiency of selection on the behavioral signs is that to achieve results, and they are positive with a high degree of reliability (P ≥ 0,99), does not require significant additional cost, but only need to integrate this feature when replenishing the production team.