195 calves were at random divided into 3 test groups and received oral (200 mg Fe/d) or intramuscular (1.0 and 1.5 g Fe on the 3rd and 36th day of the period of fluid feeding) applications of ferridextrane or no additional quotas of iron (control group) and a limited supply of milk replacer and skim milk as well as ad libitum supply with concentrated feed and dried green fodder during their 56-day period in the range of the rearing farm where the calves receive fluid feed. Iron intervention was carried out without considering the individual iron content of tissue. Its effect was evaluated according to the hemoglobin content (Hb), the hematocrit (Hc) and the mean corpuscular hemoglobin concentration (MCHC) in venous puncture blood. There was no difference between the test groups as to the stabling conditions (affiliation to race and genotype, birth weight, age and live weight resp. at the beginning of the experiment, live weight gain before the beginning of the experiment). In the control group Hb, Hc and MCHC were analogous to previous epidemiologic investigations concerning the anaemia of calves. The ferridextrane interventions carried out resulted in a raised level of Hb and Hc and diminished anaemia frequency as well as the shortened duration of anaemia in this rearing period.