On the asymptomatic salmonella infection of swine herds
1989
Biro, G. | Jayarao, B. | Kovacs, S.
On four farms (A,B,C,D) the following topics were studied: 1. Incidence and distribution of different serotypes of Salmonellae in the faeces of pigs (three samplings, conforming, different breeding phases). 2. Detection of possible sources of infections on the farms. 3. Diagnosis of Salmonellae were detected in the fecal specimens originating from the four farms, however, the rate of excreting animals was different (1-34 per cent). Serotypes isolated from the fecal specimens varied between 1 and 5. Of them, S. derby of phage type 25 was the most common. On three farms (A, D, B) the number of Salmonella carriers was high. On these farms sows proved to be the sources of S. derby serotype. Breeding animals were selected from the growing and fattening pigs on that farms (semi-closed system) which promoted the survival of the same serotype in the stock. Infection of young animals was also diagnosed, however, only pigs older than 80 days proved to be permanently excreting animals. (The infection of boars was the slightest.) Salmonellae were isolated also from the feeds and feed supplements. However, their serotypes differed from those found in the fecal specimens of pigs. This indicates that feeds and feed supplements can introduce new serotypes onto the farms without domestication. Feeding of whey of cheese industrial origin proved to be more advantageous than the conventional feeding methods. The lowest was the number of Salmonella excerting animals in farm C where - besides systematic cleaning and desinfections - whey was also fed.
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