This research was aimed at evaluating the effect of mineral-vitamin supplement withdrawal associated to reduction of inorganic phosphorus level and addition of phytase in feed on iron metabolism of finishing-phase pigs. Erythrocyte and reticulocyte count, serum iron, ferritin and transferrin quantification was performed. Forty eight hybrid swine females with initial average weight of 60kg were allotted to a completely randomized experimental design with six with four replications of two animals each. Blood was drawn from a group of twenty four 100kg animals and from a second group of twenty four 120kg animals. No differences (P>0.05) were observed in erythrocyte and reticulocyte count or serum iron and transferrin quantification. However, ferritin levels were increased in 100kg animals fed basal feed without mineral/vitamin supplement and inorganic phosphorus with phytase when compared to animals fed basal feed without mineral/vitamin supplement with inorganic phosphorus with phytase. The enzyme, even in the absence of supplementation, assured the maintenance of iron reserves in the body. Difference as mentioned above was not detected in 120kg animals. The results of this work suggest that withdrawal of vitamin and mineral supplement combined with reduction of inorganic phosphorus and addition of phytase do not lead to significant changes in iron metabolism.
erythrocyte count; iron homeostasis; serum ferritin; serum iron; serum transferrin
