Microencapsulated bacteriophages incorporated in feed for Salmonella control in broilers.

Bacteriophage inclusion as a feed additive could offer the prospect of its en masse application and reduce the intestinal carriage of Salmonella by broiler chickens. The objective of this study was to evaluate the application of microencapsulated phages as a strategy to control Salmonella and assess the impact of their use during the broiler rearing period. One-hundred one-day-old chicks were randomly divided in two identical poultry houses according to the two experimental groups (control vs Φ-treated group) simulating field production conditions. Half of the animals in each experimental group, were challenged with 105 CFU/bird of Salmonella Enteritidis per os. In the Φ-treated group, microencapsulated Salmonella-phage encapsulated in Eudragit®L100 (a pH-responsive formulation) were incorporated in the starter diet feed. To assess Salmonella colonization, excretion and diffusion, cecum samples, cloacal swabs and boot swabs were taken weekly. Salmonella detection was based on ISO 6579-1:2017 (Annex D). Salmonella colonization was significantly reduced in most of the rearing period, meanwhile the excretion was significantly reduced on the 2nd, 4th and 5th week of rearing. Moreover, Salmonella contamination of the farm environment was eliminated at the end of the cycle. This study provides important insights into the potential use of phages as a preventative and biocontrol strategy against Salmonella infection from farm-to-table.