Effectiveness of Five Feed Additives in Chicks Infected with Salmonella enteritidis Phage Type 13A

Abstract

Five feed additives, (Lactobacillus, lactose, organic acids, multiple probiotics, and egg powder) either commercially available or experimental, were evaluated in two experiments for their effectiveness in preventing gut colonization and organ invasion in chicks infected with serotype Salmonella enteritidis (S. enteritidis) phage type 13a. Chicks were infected at one or four days of age by placing into their crops approximately 104 colony forming units of S. enteritidis. None of the treatments prevented gut colonization or organ invasion when compared to untreated controls, regardless of whether the chicks were challenged at day one or day four. In all treatments, gut colonization and organ infection declined during the six-week experimental period. The decline was more rapid in treated groups than in the untreated controls. Most of the differences were not statistically significant at P < .05. Significant differences were more often seen with feed containing 5% egg powder than with other treatments. We conclude that none of the feed additives used in the two experiments presented here can be relied upon s the only measure for preventing S. enteritidis infection.