Аннотация
The paper presents the results of a comprehensive bacteriological study of the prevalence of salmonellosis among chickens of different age groups at three poultry farms. The research material was samples taken from chickens aged 2 to 20 days, 50 samples from each farm. The frequency of Salmonella bacteria release was assessed, the age dynamics of infection and the comparative epizootic situation in poultry farms were analyzed. It was found that the highest frequency of positive samples is detected in young chickens (4-6 days old), which indicates a possible early infection of the young. During the cultivation of isolates of Salmonella enteritidis, Salmonella typhimurium and Salmonella infantis, characteristic cultural and morphological features on selective diagnostic nutrient media, as well as features of bacterial population growth in accordance with the classical S-shaped curve, were described. As a result of the conducted studies, it was found that the prevalence of salmonellosis among chickens in the poultry farms studied has a pronounced age dependence and inter-farm differences. The maximum detection rate of the pathogen was observed in young chickens, mainly in the first 4-6 days of life, which suggests the role of vertical transmission or infection in the first days after hatching. The data obtained indicate the heterogeneity of the physiological state of the isolates and the varying degrees of intensity of the epizootic situation in the farms studied, which is of practical importance for the development of preventive measures and optimization of veterinary and sanitary control. Taken together, the data obtained emphasize the need to strengthen veterinary and sanitary measures in the early period of chicken rearing and can be used in the development of programs for monitoring, prevention and control of salmonellosis in poultry farms.