Purpose: This study was conducted to determine the efficacy of Diamond V Original XPC in reducing pre-harvest Salmonella in broiler chickens or turkeys in commercial processing plants, including evaluation of virulence and antibiotic resistance.
Methods: For broiler chickens, 17 houses from three different companies, age approximately 38 d, were selected; 10 were fed a ration that included 1.25 kg/t Diamond V Original XPC (XPC), and seven were fed a typical ration (CON). For turkeys, nine tom turkey houses from two companies were fed either XPC (four houses) or CON feed (five houses) to approximately 139 d of age. One cecum was collected from each of 50 birds from each house (850 chicken samples; 450 turkey samples) during evisceration at commercial processing plants, and analyzed for Salmonella prevalence and numbers, with positive samples tested for virulence and antibiotic resistance.
Results: Prevalence of broiler chicken Salmonella was significantly (P< 0.05) lower for XPC than CON samples (7.6 vs. 46.3%, respectively). Average numbers of Salmonella were lower for XPC than CON (28 vs. 417 CFU/g, respectively). Virulence, as measured by cell culture invasiveness, was less in XPC than CON isolates (0.16 vs. 1.18%, respectively). Antibiotic resistance (for florfenicol, enrofloxacin, and ceftiofur) averaged 1.0% for XPC and 1.02% for CON isolates. Prevalence of turkey Salmonella was reduced in XPC as compared to CON (5.3 vs. 18.7%, respectively). Salmonella numbers were also reduced by XPC vs. CON (8.3 vs. 88.6 CFU/g). Virulence was lower in XPC (0.19%) than CON (1.09%). Resistance to antibiotics was 3.28% for XPC vs. 13.05% for CON isolates.
Significance: XPC reduced cecal Salmonella prevalence, numbers, and virulence in commercial broiler chickens and turkeys. Results show XPC is an effective pre-harvest intervention.