Salmonella spp. infection is considered a crucial trouble of the poultry industry in Bangladesh. Hence, this study was aimed to estimate the seroprevalence of Salmonella spp. in poultry along with biosecurity practices that are associated with this Salmonella spp. infection. The study was conducted during the period from January to September, 2021 in Mymensingh and Gazipur district of Bangladesh. A total of 314 samples were considered to determine the seroprevalence. Seroprevalence was determined by performing the rapid serum plate agglutination test. The result revealed that the overall Salmonella spp. seroprevalence was 47.77% in the study area. The higher seroprevalence was in Mymensingh (51.59%) than Gazipur (45.21%) without significant (p>0.05) difference. The highest seroprevalence was in broiler (51.33%) where in layer and sonali was 32.67% and 16% respectively. Seroprevalence was significantly (p2000 to <2500 had significantly (p<0.05) higher (71.43%) seroprevalence. In broiler farms, 15 to 30 days old birds had significantly (p<0.01) higher (77.05%) seroprevalence than other age. Among the different categorical level of biosecurity practices, the poultry farms that used surface water (OR=0.182, 95% CI=0.106-0.314); disinfectant regularly (OR=0.296, 95% CI=0.171-0.511); having density of 8-10 birds/meter2 (OR=0.379, 95% CI=0.219-0.654); cleaned waterer and feeder regularly (OR=0.503, 95% CI=0.294-0.862); and having visitor restriction (OR=0.375, 95% CI=0.219-0.643) showed lower tendency (p<0.001) to seroprevalence. In brief, Strict farm hygienic practice and biosecurity measures are significantly linked to decrease the Salmonella spp. seroprevalence.

Mycoplasma gallisepticum (MG) infection is considered as one of the significant problems for the poultry industry in Bangladesh. Therefore, this study was to determine the seroprevalence of MG in poultry (layer, broiler, and Sonali) and the impact of biosecurity strategies. The study was carried out in the Mymensingh and Gazipur districts of Bangladesh from January to September 2021. A total of 338 serum samples were considered for the Serum Plate Agglutination (SPA) test. Findings indicated 56.80% overall seroprevalence, and comparatively, Mymensingh had a greater seroprevalence (59.02%) than Gazipur (54.19%). The highest seroprevalence (63.87%) was observed in layers, whereas 56.55% and 45.95% were in broilers and Sonali, respectively. Considering the seasonal variation, winter seasons had a considerably (p<0.05) higher chance of seroprevalence than summer, indicated by 83.33% and 68.35% in layer and broiler, respectively. Flock size has a meaningful (p2000 to <2500. In logistic regression, MG seroprevalence was significantly (p1000 meters from nearby farms (OR=0.485; 95% CI: 0.289-0.812), used disinfectant regularly (OR= 0.362; 95% CI: 0.214-0.614), controlled the rodents (OR=0.374; 95% CI: 0.222-0.63), controlled the visitors (OR=0.553; 95% CI: 0.331-0.926), had well ventilation (OR=0.300; 95% CI: 0.178-0.503) and cleaned the waterer-feeder regularly (OR=0.518; 95% CI: 0.307-0.876). In short, reducing the sources of contamination and transmission by ensuring strict biosecurity measures could be the strategy for controlling MG seroprevalence.