1Probiotic 1 (PRO1) = one-time spray-on application of 5 g/2,000 birds of a probiotic consisting of a combination of Lactobacillus
acidophilus, Enterococcus faecium, Lactobacillus plantarum, and Pediococcus acidilactici [24]; control for the feeding
trial (FCON) = organic diet with no additives; mannanoligosaccharide prebiotic (MOS) = inclusion in the feed of 4 lb/ton
(starter) and 2 lb/ton (grower) of a prebiotic derived from the cell walls of the yeast Saccharomyces cerevisiae [23]; probiotic 2
(PRO2) = inclusion in the feed of 2 lb/ton (starter) and 1lb/ton (grower) of a probiotic consisting of L. acidophilus, Lactobacillus
casei, Bifidobacterium bifidium, and E. faecium [24].
2Odds ratio estimates are ratios of probabilities calculated by using the following equation: (probability of finding Salmonella
for additive/probability of not finding Salmonella for additive)/(probability of finding Salmonella for control/probability of not
finding Salmonella for control).