Toxic Effect of Vitamin A in Growing Broilers

Abstract

This study was performed to evaluate the toxic effect of hypervitaminosis A on the biological and metabolic parameters of broiler youngchicken. The results of the present study indicated an adverse effect ofhypervitaminosis A on the growing broiler. Clinical signs represented byskeletal abnormalities, swelling of the knee joint, lameness, increasedbone fragility, ascitis, edema, macro and micro lesions of the examinedorgans(especially liver, kidney and bone). Bone fragility test showedincrease in long bone thickness and increased fragility positivelyaccording to dose. The toxic effect of vitamin A on bone marrow wasobvious as the histopathological exam appeared replacement of redmarrow with fatty tissue. Histopathological exam revealed lesions in theexamined tissues (such as liver, kidney, bone, bone marrow) varies inseverity that increased according to increase of the dose.