The aim of this study was to examine whether and to what extent the addition of potassium diformate (pdf) or free organic acids (fpa) to the diet and the grinding intensity might affect the course of infection and the passage of orally applied Salmonella and Escherichia coli in pigs. Experiments were carried out using 80 reared piglets allotted to four groups. Pigs were fed pelleted diets ad libitum (except during a 15 h feed-withholding-period before infection). The control diet contained finely ground cereals (2 mm screen). To two test diets (also finely ground) 1.2% pdf, 0.9% organic acids (75% formic and 25% propionic acid, fpa) respectively were added. The fourth diet (without acids) was based on coarsely ground cereals (6-mm screen). After experimental infection alternately with S. Derby or E. coli, the course of infection was examined (rectal swab technique). Pigs were sacrificed 4-5 h after a further oral application of approximately 10(9)-10(10) CFU S. Derby or E. coli to determine the counts of Salmonella or E. coli in chyme (classical culture methods). Adding pdf or fpa to the diet led to reduced Salmonella shedding and resulted in significantly lower counts of Salmonella and E. coli in the stomach content indicating an improved efficacy of the stomach barrier. In the distal parts of the digestive tract, the effect was less obvious concerning counts of E. coli, whereas counts of Salmonella were reduced markedly as well. The diet based on coarsely ground cereals failed to demonstrate positive effects concerning infection and passage of orally applied bacteria as well, but this diet was also pelleted and showed unintentionally, comparable amounts of fine particles. Results obtained in this study allow the recommendation of using pdf or organic acids as additives when dietary measures against Salmonella or E. coli in pigs are required.
Chemical and microbiological analysis of bolti fish: moisture, chloride, fat, total volatile bases (T.V.B.), thiobarbituric acid value (T.B.A.), total bacterial count and coliforms were estimated in fresh bolti fish, after brining, drying and during storage at room temperature for 3 months. The moisture content decreased after drying but become stable during the storage period. Chloride increased after bringing but no noticeable changes were observed after drying and during 3 months storage. The fat content was not affected by previously processes. T.V.B. and T.B.A. increased after brining, drying and throughout storage period. The rate of increase was higher for dehydrated samples than for sun-dried ones. The reduction of total bacterial count is due to the high salt content and the lack of free water in fish tissues after drying. Coliforms were not present after brining, drying and throughout the storage periods.
Irradiating the sardine Sardinella melanura (Cuvier) with 15,000 or 23,000 rad from a cobalt source increased the storage life at 1 C in thermoregulated cabinets. During storage the rates of increase in pH, total volatile nitrogen (TVN), tyrosine value (TV), and bacteriological count (BC) were diminished by raising the radiation dose and those for TVN, TV, and BC a so by treatment with chlortetracycline (CTC). The edibility periods, as judged organoleptically, were 4 days for untreated samples, 8 and 11 days for samples irradiated at 13,000 and 23,000 rad, and 12 days for samples treated with CTC. After 8 days' storage the TVN and TV values for samples treated with CTC were lower in relation to the values just after treatment than were those for samples irradiated at either dose. At 8 days, the BC values for samples treated with CTC were 136 times those just after treatment, in comparison with 11 times for the irradiated samples; however, the counts at 8 days were less than half as high for samples treated with CTC as for those irradiated at 23,000 rad.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.