[Histological alterations in the liver and increased serum proteins in chickens fed with diet containing Saccharomyces cerevisiae].

The aim of this study was to determine the effect of diet supplemented with Saccharomyces cerevisiae (SC), on the liver morphology, serum activities of aspartateaminotrasferase (AST) and alanineaminotransferase (ALT), and the serum concentration of total proteins, albumin and the different fractions (alpha, beta, gamma) of globulin in chickens. Two groups of Hubbar x Hubbar strain chickens (each = 16), were fed with a diet T1 (commercial food without SC) and T2 (commercial food with SC) for 42 days. Thereafter, animals were sacrificed and samples of blood and liver were obtained. Macroscopic features and relative weight of livers remained in the normal ranges in both groups. High percent of T2 chickens (p < 0.05) showed hepatic alterations with proliferation/dilation of biliary ducts and increased degree of vacuolization. Tricromic stain showed elevated perivascular fibrosis in T2. The ultrastructural study showed fibroblast like cells, increased amount of collagen fibers, cytoplasm vacuolization of hepatocytes and loss of cellular and mitochondrial integrates. No significant differences were observed in the activities of AST and ALT between groups. Increased concentrations of total proteins and alpha2, beta and gamma globulins and decreased albumin were observed in the serum of T2 group. These findings may be related to a hepatotoxic effect of SC and chickens could have the risk of further increased hepatic failure with a prolonged exposition to this diet.