Immunostimulatory effect of four food additives in broiler chickens (Gallus gallus) against Gumboro and Newcastle diseases.

Abstract

Strengthening the immune system in susceptible avian species has become a highly sought after approach to protect them against infections, especially of viral origin. This study aimed to assess the impact of four food additives on immune sys­tem modulation in chicken broilers, following vaccine intake against Gumboro disease, also called infectious bursal disease (IBD), and Newcastle disease (ND). The experimental design involved 500 one-day-old chicks of Ross strain, equally dis­tributed into five groups (four treated and one control). Treat­ment products were based on antibiotics, phytobiotics (cin­namon and ginger) and a probiotic (yeast Saccharomyces cerevisiae), orally administered via drinking water. The treat­ments were carried out over three periods of different ages: on day (D) D6–D9, D21–D23 and D33–D35. The primary vaccine doses were simultaneously administered on D7, and booster doses on D14 and D21 against IBD and ND viruses, respectively. Serum samples were collected in five chickens from each group on D18 and D31. Antibody titers were ana­lyzed by ELISA for IBDV virus and by the hemagglutination inhibition test for NDV virus. The results showed that none of the four immunostimulatory adjuvants had an effect on anti­body titers against IBD virus (p > 0.05). On the other hand, especially in groups treated with ginger and yeast a positive immunostimulatory effect was observed against ND virus. However, this difference was not significant compared to con­trol (p > 0.05).