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Report no. 489Helle D. Kjærsgaard Bent Borg Jensen 12.10.2000
Effect of Formi®LHS, ACID ONE and Expandat on the prevalence of Salmonella, gastro-intestinal health and productivity in growing-finishing pigs
Abstract
The effect was measured on the prevalence of Salmonella,
gastro-intestinal health and productivity. The test comprised the
following groups:
The test was carried out in one herd with purchased piglets. Approximately one third of the pigs originated from weaner units tested positive for Salmonella, and these pigs were allocated to all pens. There was a total of 72 pigs per group divided into 24 blocks (replicates). Fewer coliform bacteria and a higher concentration of volatile fatty acids were discovered in the stomachs of pigs fed meal feed compared to the pigs fed pelleted feed (control). Addition of 1% Formi®LHS or ACID ONE to the feed reduced the amount of coliform bacteria in the stomach and caecum and caused a higher concentration of formiate/formic acid in the stomach compared to the pigs fed pelleted feed (control). These results indicate that both meal feed and pelleted feed added 1% Formi®LHS or 2% ACID ONE might reduce the prevalence of Salmonella as the microbial ecosystem was affected favourably. Addition of 1% Formi®LHS or ACID ONE reduced the population of yeast. The significance of yeast for pigs’ health status is not known. Expandat did not result in as substantial changes in the microbial ecosystem in the gastro-intestinal tract as did meal feed and an addition of 1% Formi®LHS or ACID ONE. When using Expandat, we discovered a lower content of yeast and a higher concentration of butyric acid in the stomach compared to pelleted feed (control). Measured on blood samples, there were only very few salmonella-positive pigs in this test and it was thereby impossible to establish the direct effect of the products/mixes on Salmonella. The production value, which was calculated on the basis of the achieved production results using the same price for all mixes, was poorer for groups 2 (meal feed) and 6 (Expandat) compared to group 1. The production value for groups 3-5 was not significantly different from the production value in group 1. The lower production value in groups 2 and 6 was in particular due to a poor feed conversion but also a slightly lower daily gain. In those groups there was a visibly larger feed waste despite regular adjustments of the dispensers. The poorer feed conversion was most likely due to a combination of an actually poorer conversion of the feed and a larger feed waste. The microbiological results indicate that it is possible to compound a pelleted feed that equally with meal feed can reduce the prevalence of Salmonella. Work is now continued to establish whether a “pellet-solution” may exist that can reduce the prevalence of Salmonella at the same level as meal feed without resulting in a poorer feed conversion. To read report 489 in its entirety as PDF file, please click here. |
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