[Effect of parenteral iron doses on the measurement of red blood parameters and on weight development in lambs of different breeds].

Conventionally reared male and female lambs of Merinoland- (n = 87) and Rhön sheep (n = 30) were injected at day 3 of age with 300 mg iron dextran. Body weight of the animals was determined and blood samples were taken at day 3, 10, 21 and 42 of age. Glutathione (GSH) and haemoglobin (Hb) concentrations in blood, haematocrit (PCV), mean corpuscular haemoglobin concentration (MCHC) as well as haemoglobin-type (Hb-type) and the occurrence of foetal and anaemic Hb-bands after electrophoretic separation were determined. Data were analysed by least squares procedures where the effects of breed, sex, number of lambs born, Hb-type, foetal and anaemic Hb-bands were considered as fixed factors. Independent of all fixed factors, the application of iron dextran increased daily gain from day 3 to 10 of age in all lambs treated. Mainly twins and male lambs showed higher daily gains in this period when compared with the control groups. In untreated lambs lower values for blood parameters were observed within the first week of life, but no negative influence was found in daily gain until day 42. Between Merinoland- and Rhön sheep, significant differences in GSH concentration of blood where found which were not influenced by the application of iron. Lambs with a detectable foetal band at day 42 of age showed significant lower daily gains, MCHC, and Hb-concentrations when compared with lambs lacking this band. Interactions between occurrence of anaemic band and erythrocyte measurements could not be shown.