FERRO E IMUNIDADE HUMORAL EM SUÍNOS ALIMENTADOS COM FITASE E NÍVEIS REDUZIDOS DE FÓSFORO

Abstract

Endogenous enzymes such as phytase have been widely used in swine production to increase phosphorus, amino acid and energy availability from feeds. This study aimed to evaluate the immune system through quantification of blood components associated to iron metabolism and determine humoral immune response elements in pigs fed phytase-added diets without micro minerals and vitamins and partial or total deletion of inorganic phosphorus. Forty-eight crossbred females with initial weight of 60 kg were randomly sorted into six groups of eight animals each, as follows: G1 -standard (complete) ration (control group); G2 - standard ration except that micromineral and vitamin supplement was deleted; G3 - group 2 ration with phytase, G4 - group 2 ration less 1/3 of inorganic P with phytase, G5 - group 2 ration less 2/3 of inorganic P with phytase and G6 - group 2 ration without inorganic P with phytase. Statistical difference (p>0,05) was not recorded neither in white cells and platelet counts nor hemoglobin, serum iron levels, considering all the animals in all treatments. Nevertheless, pigs up to 100 kg that consumed diet without micro minerals and vitamins, total deletion of inorganic P and phytase addition presented increased ferritin levels (p>0,05) when compared to animals fed similar diet with inorganic phosphorus and phytase. The enzyme guaranteed maintenance of iron stocks even in the absence of supplementation. Such difference was not recorded with 120-kg animals fed similar rations. Average total protein, IgG and IgM levels were not influenced by phytase, mineral and vitamin supplementation or inorganic phosphorus levels. The results demonstrate that decrease of inorganic phos-phorus, withdrawal of vitamin and mineral supplements and phytase addition in diets of finishing pigs do not lead to significant changes in hematological, biochemical and humoral immune response parameters. Key-words: Immune system seric ferritin, IgG, IgM, white cells count.