Effect of pelleting and use of lactic acid in feed on Salmonella prevalence and productivity in weaners

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Jørgensen, Lisbeth
Kjærsgaard, Helle
Wachmann, Henrik
Jensen, Bent
Back Knudsen, Knud
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International Conference on the Epidemiology and Control of Biological, Chemical and Physical Hazards in Pigs and Pork
Iowa State University Conferences and Symposia

The SafePork conference series began in 1996 to bring together international researchers, industry, and government agencies to discuss current Salmonella research and identify research needs pertaining to both pig and pork production. In subsequent years topics of research presented at these conferences expanded to include other chemical and biological hazards to pig and pork production.


The effect of the feed's form and of acidification was studied in one herd with weaners (approx. 7-30 kg). The test comprised a total of 232 pigs/group allocated to 30 replicates. Weaners were purchased from three different herds that all had a recognized Salmonella problem. The test was carried out as a randomised 2x2 factorial design with the factors meal vs. pelleted feed and-/+ 2.8% lactic acid added to the feed. Addition of 2.8 % of lactic acid reduced the number of Salmonella positive faecal pen samples. There was no significant effect of feeding meal feed compared to pelleted feed on Salmonella. The microbial results showed a reduced population of coliform bacteria in the digestive tract when acid was added to the diet. There was a higher water binding capacity and a higher dry matter (DM) concentration when using meal feed compared to pelleted feed. The viscosity in the stomach was higher in the groups given feed added acid compared to feed without acid. The production value (expresses the achieved productivity) was significantly higher in the groups receiving feed with added lactic acid. Feeding meal feed also resulted in a higher production value compared to pelleted feed. On the basis of this test, the best advice against Salmonella in weaners is to use a high concentration of lactic acid in the feed.