Neutrophil oxidative metabolism and haemogram of sheep experimentally infected with Haemonchus contortus and supplemented with selenium and vitamin E.

Abstract

The objective of this study was to evaluate neutrophil oxidative metabolism and haemogram in sheep experimentally infected with Haemonchus contortus and supplemented with selenium and vitamin E. Twenty male Corriedale sheep were utilised and distributed into four experimental groups each with five animals infected with larvae: G1--supplemented with sodium selenite, 0.2 mg/kg body weight (bw) given intramuscularly (IM); G2--supplemented with sodium selenite and vitamin E, 0.2 mg/kg bw and 2000 IU per animal, respectively, both IM; G3--supplemented with vitamin E, 2000 IU per animal IM; G4--not supplemented. A haemogram and the number of parasite eggs were determined in samples of blood and faeces, respectively, on days zero (T0), 20 (T1), 40 (T2) and 60 (T3) and nitroblue tetrazolium (NBT) assays were performed on heparinized blood samples taken on days zero, 30 and 60. A lower total leucocyte count was detected in G1 in relation to G4 at T4. Lymphocytes were reduced in G1 in relation to G3 and G4 at T3. In both non-stimulated (NBT-NS) and stimulated (NBT-S) dye reduction assays, there was reduced activity at 60 days, in relation to other times in the groups treated with selenium (G1 and G2). On the basis of results obtained, we conclude that supplementation with selenium provides better antioxidant protection to neutrophils.