Perfil oxidativo, hematologia e interação mineral em cordeiros suplementados com altas doses de ferro

Abstract

The aims of this study were to assess the hematological response, erythrocyte membrane lipoperoxidation, antioxidant status and the mineral interaction in lambs supplemented with iron. In the first study, the oxidative profile, erythrogram, and the mineral interaction were assessed in lambs with anemia due to worm infection. For doing it, 27 lambs with anemia due to worm infection were used and they were divided in three groups: Control Group (GC) n=9, Ferrous Sulphate Group (G2) n=9 and Ferric Sulphate Group (G3) n=9. The animals of G2 received 200 mg of iron in the ferrous form (Fe+2) orally daily, the animals of G3 received 200 mg of iron in the ferric form (Fe+3) orally daily, whereas the GC received no treatment. There was no statistic difference in the serum iron values and erythrogram7. Serum copper and zinc values were lower in the G2 and G3 on days 21 and 28 of the experiments, whereas faecal copper, iron and zinc excretion were higher in the same groups. The SOD levels were lower in the G2 and G3 on day 28 whereas the NPTH measurement showed a decrease on days 21 and 28. In relation to TBARS, there was an increase. It was concluded that oral supplementation with 200 mg of iron, irrespective of its form does not increase the erythrocyte response in lambs. As well as, it has antagonist action on copper and zinc, reducing its serum concentrations and increasing the faecal excretion of these minerals. Moreover, the decrease of the serum copper and zinc concentrations causes a decrease in activity of superoxide dismutase, causing an oxidative stress situation. In turn, the second experiment assessed the hematological parameters, weight gain and hepatic function in anemic lambs. It was used 27 lambs with anemia due to worm infection divided in three experimental groups: Control Group (GC) n=9, Ferrous Sulphate Group (G2) n=9 and Iron Dextran Group (G3) n=9. The animals of G2 received 200 mg of iron in the ferrous form (Fe+2) orally daily, the animals of G3 received two intramuscular injections of 25 mg/kg/body weight of iron dextran at 7-day interval, the first one on day zero of the experiment, whereas the GC received no treatment. The serum iron levels in the G3 were higher than GC and G2 on days 7 and 14 (P>0,05). In relation to erythrogram, the G3 showed a significant improvement (P>0,05) compared to GC and G2 on days 7, 14 and 21. The hepatic iron levels in the G3 were higher than GC and G2, without changing the measurement of hepatic function. OPG and leucocytes levels showed no statistic difference among the groups. It was concluded that the administration of two doses of iron dextran increases serum and hepatic concentration of this mineral, however without damage to this organ and increases erythropoiesis whereas daily oral administration of 200 mg has no influence over red blood cell serie, neither serum and hepatic levels of this mineral. Both of them do not influence leucocytes.