Avi-Lution supplemented at 250 or 500 mg per kg in feed decreases the abundance of Salmonella Enteritidis in ceca of layer pullets

Abstract

Salmonella enterica serovar Enteritidis ( Salmonella Enteritidis [ SE] ) is a foodborne pathogen that is capable of affecting shell eggs and is regulated by Title 21 of the Code of Federal Regulations. A reservoir for this pathogen is the ceca of the gastrointestinal tract in chickens. In the present study, layer-type pullets in 2 consecutive studies were not treated or treated with a feed additive that comprised a synbiotic blend of probiotic (direct-fed microbial) and prebiotic ingredients at total dietary inclusion of 250 or 500 mg kg −1 and were challenged orally with SE. At 10 d after challenge, pullets were euthanized and ceca were harvested for enumeration of SE. Pullets treated with Avi-Lution at 250 mg kg −1 were found to have a significantly ( P < 0.001) lower number of SE per g of cecal contents, where SE was approximately 1.0 log lower than control in experiment 1 and > 2.0 log lower than control in experiment 2. Pullets treated with Avi-Lution at 500 mg kg −1 also had significantly lower burden of SE in cecal contents than control, and SE burden was not significantly different between Avi-Lution treatment at 250 and 500 mg kg −1 . The reduction of SE burden in the cecal reservoir demonstrated in the present study is expected to relate to decreased external contamination of eggs by SE in laying hens and therefore is presented as a food safety precaution where intervention in live birds against SE contamination is desired.