Intestinal colonization and shedding of pathogenic bacteria in animal feces is an important factor in both human food safety and animal health. The effect of broiler feed additives flavophospholipol (FPL; Flavomycin, bambermycins) and salinomycin sodium (SAL; Sacox) given singly on the excretion of Salmonella enteritidis, Campylobacter jejuni, and Clostridium perfringens was studied following controlled infection. The incidence of shedding (number of birds with positive fecal cultures) and the degree of shedding (cfu per gram of feces in positive birds) were measured to determine the influence of these two common feed additive antibiotics on shedding rates of potential pathogens. A total of 216 Ross broiler chickens, housed in battery cages, were fed either an unmedicated feed (controls), feed containing FPL, or feed containing SAL. Feed treatment groups were subdivided into three bacterial challenge groups of 24 chicks, each receiving only one of the pathogens. Bacterial challenge was administered orally on Days 11 and 12 for Salmonella and Campylobacter and on Days 2 and 3 for Clostridium. Fecal samples were collected weekly up to 6 wk of age and cultured for presence of the target organism. The shedding rate was determined by decimal dilutions of the fecal samples. Feeding FPL resulted in a reduced (P < or = 0.05) degree and incidence of Salmonella and Clostridium shedding at 6 wk. Feeding SAL reduced (P < or = 0.05) the incidence of Salmonella shedding at 6 wk. Neither feed additive affected the incidence nor the degree of Campylobacter shedding. The results of this study indicate that these feed additives may reduce the incidence of these potential human and animal pathogens in preslaughter broilers.