Ciência e Tecnologia Veterinária

Dietary Supplementation of Bacillus subtilis Probiotics Improves Growth Performance and Immune Response of Ducks-Experimentally Infected with Riemerella Anatipestifer

Abstract

Walaa Fathy Saad Eldin Ibrahim, Lammah Abdel Sameaa and Wageh Sobhy Darwish

Riemerella anatipestifer (RA) is a major bacterial disease affecting the poultry industry worldwide, particularly causing high economic losses in duck farms in Egypt. The objective of this experimental study was firstly to investigate the effects of RA-experimental infection on the morbidity and mortality rates and growth performance in Pekin ducks. Secondly the effects of RA on the transcriptomic expression of the immune related genes (interleukins (IL)1β, 6, 8, 10 and 17A) in the infected ducks were also examined using real time quantitative PCR. Thirdly, the protective effects of Bacillus subtilis (B. subtilis) as a probiotic dietary supplementation against RA infection in ducks were also investigated. The achieved results indicated that the mortality rate in RA-experimentally infected group was 80% and this percentage was reduced to 20% when birds received probiotics in their diet before challenge with RA. Furthermore, RA infection reduced the average feed intake, average body gain with poor average feed conversion ratio, while dietary supplementation of probiotics to ducks ’ feed significantly improved growth performance parameters. RA modulated the gene expression of the immune related genes, however, probiotics significantly upregulated mRNA expressions of the examined cytokines as a mechanism for the protective roles of probiotics against RA infection in ducks. Therefore, it is highly recommended to use probiotics dietary supplementation in duck farms in order to improve the growth performance and reduce the disease burden.