Effects of selenium-chitosan on intestinal microflora, intestinal histomorphology, and immune response of broiler chickens

Abstract

In a companion paper, the effects of Se-chitosan as organic Se, Na selenite, vitamin E, and their various combinations on growth performance, carcass traits, meat quality, and blood indices of broiler chickens have been reported. In this part of the paper, their effects on intestinal microflora, intestinal histomorphology, and immune response were investigated. A total of 480 one-day-old broiler chickens were randomly assigned to the Se source (inorganic and organic), Se inclusion (0.15 and 0.3 mg/kg), and vitamin E (0 and 80 IU/kg) in a 2 × 2 × 2 factorial arrangement of treatments with 5 pens per treatment and 12 broiler chickens per pen. Broiler chickens fed diets supplemented with Se-chitosan or 0.3 mg Se/kg had lower coliform counts and greater lactic acid bacteria/coliform ratios in ileum and cecum (P < 0.05). Dietary supplementation with Se-chitosan increased villus height/crypt depth ratio (VH/CD), villus surface area, and goblet cell density in ileum and jejunum (P < 0.05). Furthermore, broiler chickens fed diets supplemented by 0.3 mg Se/kg or vitamin E had greater villus height, VH/CD, villus surface area, and goblet cell density and lower crypt depth, and epithelial cell layer thickness in jejunum (P < 0.05). Dietary supplementation with Se-chitosan increased total antibody response to sheep red blood cells (SRBC), IgG, and antibody response to Newcastle disease virus (P < 0.05). Interaction between Se source and vitamin E content showed that broiler chickens fed Se-chitosan plus vitamin E had lower ileal coliform counts and greater jejunal villus height, VH/CD, and villus surface area and serum total antibody response to SRBC compared to broiler chickens fed Na selenite with or without vitamin E (P < 0.05). It could be concluded that, compared to the use of Na selenite alone or with vitamin E, the inclusion of Se-chitosan as a novel source of Se plus 80 IU vitamin E/kg could improve intestinal microflora, intestinal histomorphology, and immune response.