Muscle fiber properties are important for beef meat production: quantity and quality. Fetal life represents crucial phase for the acquisition of muscle properties. Conditions of gestation of the cow will have impacts on muscle development. Very few studies concern the effect of nutrition restriction during gestation in cattle. Our objective was to analyze the impact of nutrient restriction at specific gestational stages on fiber properties of Semitendinosus muscle. Cross bred beef cows were fed to nitrogen and energy recommendations (CCC) or restricted to 60% of recommendations for the first 85 or 140 days post conception followed by realimentation to recommended protein and energy levels (RCC and RRC respectively). The morphology and properties of fibers were analyzed by immunohistochemistry with specific anti myosin heavy chains antibodies. The main effects of undernutrition were observed at 254 days. The most important effect is the presence of lower proportions of small fibers expressing fetal myosin heavy chain in RCC and RRC groups in comparison to CCC. As these fibers correspond to the third generation giving rise to IIA fibers, this could have consequence on the proportion of IIA fibers of this muscle.