Skip to main content


Studies have shown that supplementing probiotics in a nasal spray can provide prophylaxis against upper respiratory tract infections. Previously, we found that spraying with Bacillus reduced the concentration of atmospheric ammonia and airborne microbiological aerosols in broiler houses. In the present study, we evaluated the effects of spraying with Bacillus amyloliquefaciens on the respiratory mucosal barrier in broilers. Two trails were conducted simultaneously in four environmentally controlled chambers. In each trail, 320 1-d-old male broilers were randomly assigned to control (CON) and B. amyloliquefaciens (BAQ) group. Eight cages containing 20 birds per cage were placed in two chambers. The BAQ group chambers were sprayed with B. amyloliquefaciens at 4 × 109 CFU/m2 each day for 42 d. Spraying with B. amyloliquefaciens increased average daily gain and average daily feed intake in broilers (P < 0.01), but had no effects on FCR (P > 0.05). The relative weights of the bursa (21 d) and spleen (42 d) were higher in the BAQ group (P < 0.05). The serum IgG, IgM (21 d), and IgA, Ig M (42 d) levels were improved in BAQ group (P < 0.05). The sIgA levels in tracheal lavage fluid were significantly higher in the BAQ group than the CON group (P < 0.05). Furthermore, treatment with BAQ downregulated IL-6 and IFN-γ (P < 0.05), but upregulated IL-2, occludin, and mucin-2 (P < 0.05). In addition, the number of acidic goblet cells was significantly higher in the tracheas of treated broilers than untreated broilers (P < 0.05). In conclusion, spraying with B. amyloliquefaciens may help to enhance the growth performance and improve the respiratory mucosal barrier in broiler chickens.

Keywords: Bacillus amyloliquefaciens spray; broiler; growth performance; immune function; respiratory mucosal barrier.

Research Insights

SupplementHealth OutcomeEffect TypeEffect Size
Bacillus amyloliquefaciensEnhanced Immune StatusBeneficial
Bacillus amyloliquefaciensImproved Growth PerformanceBeneficial
Bacillus amyloliquefaciensImproved Respiratory Mucosal Barrier FunctionBeneficial
⬆ Back to top
Supplement Research and Comparison Website: evidence-based information about supplements, their benefits, potential risks, and their efficacy.
Receive updates about our products, services, sales, and special offers. Unsubscribe anytime. See our Privacy Policy for details on how we handle your information.

Join Our Community

Use to get in touch.