Forty-eight Dorper lambs, comprising 24 ram and 24 ewe lambs, were divided into four groups of six ram and six ewe lambs each and were allocated to one of the following feeding levels: ad libitum, 80%, 65% or 50% of ad libitum Intake. The ad libitum diet had a metabolizable energy content of 10,15 MJ /kg and a crude protein content of 15,44%. The lambs were weaned at 120 days (mean weaning mass = 24,3 ± 4,3 kg). After the nine-week restriction phase, all lambs were given ad libitum feeding until the ewe lambs reached a body mass of 45 kg and ram lambs a mass of 55 kg. Daily feed intake, growth rate and efficiency of feed utilization were calculated during the restriction and realimentation phases. During the restriction phase, digestibility of the diet increased whereas growth rate and efficiency of feed utilization decreased with increasing restriction. With the onset of the realimentation phase, the ME intake of ewe and ram lambs increased with decreasing ad libitum intake. The growth rates of ewe lambs increased at the same point by 8,9%, 45,8% and 251,4%, and those of ram lambs by 104,5%, 104,6% and 174,2% at the 80%, 65% and 50% intake levels, respectively. In spite of the increase in growth rate during the realimentation phase, the growth rate of the restricted ewe lambs could not better or equal the growth rate of the ad libitum group at a specific live mass, while the growth rate of the restricted ram lambs bettered the rate of the ad libitum group. No differences in the total amount of protein in the body could be detected between sexes on the respective feeding levels. The deposition rate of protein decreased progressively as the restriction during the restriction phase increased. During the realimentation phase, protein deposition of all the previously restricted groups increased, while that of the ad libitum group declined slightly. No differences within sex groups in the proportion of fat at different body masses could be detected between different feeding levels. The deposition rate of fat declined progressively as the restriction during the restriction phase increased. Feeding levels did not affect the fat : protein ratio of ewe and ram lambs. According to data collected during the trial, the efficiency of feed utilization in ewe lambs decreased with an increase in restriction in feed intake, while that of ram lambs increased.