Abstract

Poultry litter is used in fish farms as fertilizer thus integrated fish-duck farming is common in some areas of Egypt. Salmonella bacteria may be present in poultry litter and contaminate fish ponds and infect duck farms. To investigate incidence and prevalence of Salmonella infection in integrated duck-fish farms, 50 litter samples, 200 cloacal swabs from integrated duck farms, 60 liver samples from integrated duck farms and 69 water samples from the fish pond were collected. Results revealed the isolation and identification of 19 Salmonella spp. belonging to 14 different serotypes (4 isolates from litter, 2 isolates from fish pond water, 8 isolates from cloacal swabs of ducks and 5 isolates from ducks liver). Fifty, one-day-old Pekin ducks were experimentally infected with five chosen Salmonella serotypes (S. Bargny, S. Tshingwe, S. Uganda, S. Kentucky, and S. Enteritidis). The results from experimental infection revealed clinicopathological findings including degeneration and necrosis in the liver, lymphoid depletion and macrophage infiltration in the spleen and enteritis. Mortality ranged from 28.6% in S. Bargny, S. Enteritidis and S. Kentucky and increased to 42.9% in S. Uganda and reached up to 100% in S.Tshingwe. Body weight gain decreased by 16% in S. Uganda and exceeded to 23.9% in S. Kentucky and decreased by 31% in S. Bargny and S. Enteritidis as compared to the control group. Feed conversion ratio was recorded and ranged from 5.1, 5.11, 4.98, 5.15 and 4.02 in S. Bargny, S. Uganda, S. Kentucky, S. Enteritidis, and control group, respectively. In conclusion, different species of Salmonella can affect integrated duck-fish farms and cause high mortality as well as a decrease in feed intake, feed conversion ratio, and body weight gain.