Competitive Exclusion of Salmonella enteritidis in Leghorn Chicks: Comparison of Treatment by Crop Gavage, Drinking Water, Spray, or Lyophilized Alginate Beads

SUMMARY. The protective effect of cecal bacteria cultures on Salmonella enteritidis cecal colonization was evaluated. Competitive-exclusion cultures were administered by crop gavage, in first drinking water, by whole body spray, or encapsulated in alginate beads and provided in feed pans. Leghorn chicks were treated with cultures of cecal bacteria on the day of hatch and challenged orally with 104 S. enteritidis 2 days after treatment. Salmonella cecal colonization was evaluated 7 days after challenge. No Salmonella organisms were detected in the ceca of chicks treated with cecal cultures by crop gavage. Chicks treated with cecal cultures in the drinking water or by spray application showed comparable protection and significant decreases (P < 0.05) in the number of Salmonella in the cecal contents compared with untreated controls. The consumption of cecal bacteria encapsulated in alginate beads significantly decreased (P < 0.05) Salmonella cecal colonization compared with control treatment, but it provided less protection than the other treatment methods evaluated. RESUMEN. Exclusi6n competitiva de Salmonella enteritidis en pollitos Leghorn: Comparaci6n del tratamiento con sonda al buche, agua de bebida, aspersi6n o capsulas liofilizadas. Se evalu6 el efecto protector sobre la colonizaci6n cecal por Salmonella enteritidis. Se usaron cultivos de exclusi6n competitiva con bacterias cecales, administradas por medio de sonda al buche, agua de bebida, aspersion directa al cuerpo, o administradas en capsulas en las bandejas de alimento. Pollitos leghorn fueron tratados al dia de edad con cultivos de bacterias cecales y desafiados oralmente con dosis de 104 S. enteritidis dos dias despues del tratamiento. La colonizaci6n cecal por Salmonella fue evaluada dos dias despues del desafio. No se detectaron Salmonellas en el ciego de los pollitos tratados con cultivos cecales directamente en el buche. Los pollos tratados con cultivos cecales en el agua de bebida o por aspersi6n mostraron una protecci6n similar, obteniendose una disminuci6n significante (P < 0.05) en el numero de Salmonellas en el contenido cecal, comparado con los controles no tratados. El consumo de bacterias cecales encapsuladas disminuyo significantemente (P < 0.05) la colonizaci6n cecal por Salmonella comparada con los pollitos controles, pero di6 menos protecci6n que los otros metodos de tratamiento evaluados.