Immunoprotective potential of egg yolk antibodies (IgYs) in controlling necrotic enteritis in broiler chickens.

Abstract

The present study was designed to evaluate the immunoprotective role of specific egg yolk antibodies (IgYs). Eighty, day-old broiler chicks were purchased and divided into four groups (G, G, Gand G). Gserved as control negative, while C. perfringens type A (1 ×10cfu/mL) was given via oral route from days 17-19 of the experiment in group G(control positive). Groups Gand Gwere passively immunized with 1 mL of anti-clostridial IgYs per bird via per os (days 21-24) and IM routes (days 22 and 24), respectively. The birds in group Ghad higher feed conversion ratio (FCR) values and reduced relative weight of immune organs. The values of various immunological assays inlcuding hemagglutination inhibition titer values against Newcastle disease virus (NDV), titer values of total immunoglobulins and IgY after anti-sheep RBCs (anti-SRBCs) injection and phagocytic potential of circulating macrophages were lower in Gcompared to G. In groups Gand G(passively immunized), these pathological alterations were comparatively less severe or absent indicating the immuno-protective role of anti-clostridial IgYs against experimental infection. The results suggest that IgYs could be an effective alternative to antibiotics for controlling necrotic enteritis in poultry, with potential benefits in view of animal health and production costs.