Two studies were carried out to investigate on the nutritional status of newborn foals also related to some mare milk characteristics. In the first study 5 foals born from Franch Montagnes x Bardigiana mares were muzzled and artificially reared in order to get more information on foals' nutritional status during the first weeks after birth. Mares' milk characteristics were also investigated. In a second study, the effects of fish oil supplementation, source of omega 3-PUFA, to five mares' diet on some plasma metabolites and on growth rate of the foals were evaluated according to a switch back design. Although the high variability between foals, remarkable changes in the blood chemistry and in some metabolic profiles were observed in artificially reared or suckling foals during the first weeks of extrauterine life.