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Sixty Angus-cross steers were used to compare the effects of recycled poultry bedding (RPB) stacking method and the inclusion of monensin in growing diets on performance. Steers were individually fed balanced, growing diets for a period of 84 d. The diets were control (CON), CON + monensin (CON+M), deep-stacked RPB (DS), DS+M, shallow-stacked RPB (SS), and SS+M. The CON diets contained corn, soybean meal, corn silage, and cottonseed hulls. In the RPB diets, 35% of the silage, cottonseed hulls, and soybean meal was replaced with RPB (as-fed basis). At the end of the growing period, 30 steers, representing all treatment groups, had liver biopsies for trace mineral analysis and ruminal fluid samples to assess pH, VFA, and ammonia concentrations. All steers had blood samples drawn at the end of the growing period for analysis of Se and urea N. Steers were transported 466.6 km to simulate shipping stress and started on a finishing diet for a 120-d period. Intake, ADG, and G:F were monitored throughout the trial. Steers fed CON diets had higher ADG, DMI, and G:F than SS, and higher ADG and G:F than DS (P < 0.05) during the growing period. Steers fed DS diets had higher DMI than SS (P < 0.05) during the growing period. Inclusion of monensin in the growing diets increased G:F and decreased DMI (P < 0.05). Steers from the RPB treatments started the finishing period at lighter BW than steers fed CON diets (P < 0.05). During the finishing period, steers fed SS diets had higher DMI than steers fed CON diets (P < 0.06), whereas steers fed DS diets were intermediate. At slaughter, steers fed CON diets had higher hot carcass weights and quality grades than steers fed SS diets (P < 0.07), whereas steers fed DS diets were intermediate. Results indicate that steers fed RPB consumed it better when processed by deep stacking before consumption, that carryover effects of RPB into the finishing phase were minimal, and inclusion of monensin did not affect consumption of RPB diets.

The ability of ruminants to utilize nutrients presentin waste from other species provides an opportunity forefficient use of waste and a cost-effective source of cattlefeed.1 Processed broiler litter has been fed to beef cattlein the U.S. for several decades.2 Recently, however, concernshave been raised about litter as a potential sourceof pathogens, including Salmonella species, that may bespread from poultry to cattle and ultimately to consumers.3,4,5 This project was designed to determine whether feeding broiler litter increases the prevalence of Salmonella shedding in backgrounded beef calves.

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.