Probiotic Effect of Limosilactobacillus fermentum on Growth Performance and Competitive Exclusion of Salmonella Gallinarum in Poultry
Pakistan Veterinary Journal
Abstract
Fowl typhoid, an acute or chronic systemic infection of poultry is caused by Salmonella Gallinarum.It causes considerable economic losses in poultry in different countries including Pakistan.The aim of this study was to evaluate the effect of two previously characterized indigenous Limosilactobacillus fermentum strains (PC-10 and PC-76) on competitive exclusion of Salmonella Gallinarum in poultry gut.Day old chicks (n=90) were equally divided into six groups.Group 1 was kept as negative control and group 2 was positive control.Birds in group 3, 4 and 5 were administered with Limosilactobacillus fermentum strains PC-10, PC-76 and commercial probiotic, respectively from day 1-35.Group 6 was treated with antibiotic (florfenicol 30mg/kg) following the post infection of S. Gallinarum.All experimental groups except the negative control were challenged with S. Gallinarum (10 8 CFU/bird) on day 21.The effect of probiotics on gut microbiota; Lactobacillus, total coliform and Salmonella were enumerated before and after the administration of challenge organism.Weight gain, feed conversion ratio and immune response to Newcastle disease and infectious bursal disease vaccine were determined.The results showed that Limosilactobacillus fermentum PC-10 and PC-76 significantly (P˂0.05)decreased the growth of S. Gallinarum (3.92±0.37 vs 3.99±0.22log10CFU/g) in comparison to positive control group (6.88±0.2log10CFU/g) on day 35.The administration of these probiotics led to a significant increase in Lactobacillus count (>2log10) and reduction in coliforms count (1-2log10) in broilers.The probiotic fed groups exhibited less lesion scores and mortality rates compared to positive control group.Moreover, the broiler bird fed with Limosilactobacillus fermentum PC-10 and PC-76 group exhibited higher weight and immune response.Based on these findings, it was concluded that Limosilactobacillus fermentum PC-10 and PC-76 may be used as potential probiotics for targeted mitigation of S. Gallinarum in broilers.