Evaluation of Salmonella shedding in cattle fed recycled poultry bedding

Abstract

Recycled poultry bedding (RPB), contaminated with Salmonella, was fed to beef calves to determine if it would increase the prevalence of detectable Salmonella faecal shedding. 60 Angus crossbred steer calves were placed on balanced rations containing Salmonella-contaminated recycled poultry bedding that had been properly or improperly stacked, or fed a control diet for an 84-d growing phase. After the growing phase, the calves were transported (for 12 h) to simulate shipping stress and then fed a single finishing diet. Faecal samples were collected from each calf and cultured for Salmonella prior to the start of the trial, every 14 days during the growing phase, 24 hours after transport and every 28 days during the finishing phase. At the end of the finishing phase, scrapings from the ileocaecal mucosa were collected at the abattoir and cultured. Dietary components and total mixed rations were sampled and cultured weekly for Salmonella. Other than the poultry bedding at delivery, none of the dietary components or calves were culture-positive for Salmonella at any time during the feeding periods or after transport. One calf that had been on a RPB diet during the growing phase was positive for Salmonella norwich at postmortem collection; however, it was not established that this was the same serotype of Salmonella cultured from the RPB. We conclude that feeding a known Salmonella-contaminated feed source as a part of a balanced ration did not increase the prevalence of detectable Salmonella shedding in calves over the published prevalence.