Dietary Weizmannia faecalis DSM 32016 probiotic supplementation reduces Salmonella colonization and supports growth performance in broilers challenged with Salmonella enterica serovars.

Salmonella colonization in broilers remains a major challenge for poultry production and food safety, increasing the need for non-antibiotic nutritional strategies that support intestinal health and pathogen control. This research evaluated the efficacy of Weizmannia faecalis DSM 32016 (WF-32016) as a dietary probiotic supplement in reducing Salmonella colonization and supporting intestinal health and growth performance in broilers under experimental challenge conditions. Two complementary experiments were conducted using Ross 308 broilers. In Study I, 216 birds were allocated to six treatments representing the combination of two Salmonella enterica serovar Typhimurium challenge conditions (non-challenged and challenged) and three dietary regimens: an unsupplemented control, WF-32016 at 400 g/t during the starter phase and 200 g/t during the finisher phase (WF 400/200), or WF-32016 at 400 g/t during both phases (WF 400/400). Growth performance was evaluated throughout the experimental period, and cecal microbial populations, serum malondialdehyde (MDA) concentration, and ileal histomorphology were assessed on day 35. In Study II, 108 birds were allocated to three treatments: non-challenged control, Salmonella enterica serovar Minnesota-challenged control, and Salmonella Minnesota-challenged birds receiving WF-32016 at 400 g/t during the starter phase and 200 g/t during the finisher phase (WF 400/200). Cecal Salmonella colonization and intestinal permeability were assessed on days 7 and 28. In Study I, Salmonella challenge impaired daily weight gain, feed conversion ratio, and production efficiency factor, particularly during the finisher and overall periods. WF-32016 supplementation improved performance in challenged broilers, with the WF 400/400 regimen producing the most consistent response. Cecal Salmonella enumerations were numerically reduced by WF-32016 in challenged birds, with the greatest reduction observed in the WF 400/400 group. Supplementation also lowered serum MDA concentrations and numerically increased cecal Lactobacillus populations, while ileal morphology was not adversely affected. In Study II, WF-32016 significantly reduced cecal Salmonella colonization on both days 7 and 28, although intestinal permeability did not differ among treatments. Overall, dietary WF-32016 reduced Salmonella colonization and supported broiler performance under enteric challenge conditions, indicating its potential as a probiotic strategy for improving poultry health and productivity.