Effect of starter culture inoculation on feed hygiene and microbial population development in fermented pig feed composed of a cereal grain mix with wet wheat distillers’ grain
Article first published online: 22 MAY 2009
© 2009 The Authors. Journal compilation © 2009 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 108, Issue 1, pages 129–138, January 2010
How to Cite
Olstorpe, M., Axelsson, L., Schnürer, J. and Passoth, V. (2010), Effect of starter culture inoculation on feed hygiene and microbial population development in fermented pig feed composed of a cereal grain mix with wet wheat distillers’ grain. Journal of Applied Microbiology, 108: 129–138. doi: 10.1111/j.1365-2672.2009.04399.x
- Issue published online: 10 DEC 2009
- Article first published online: 22 MAY 2009
- 2008/1774: received 16 October 2008, revised and accepted 12 May 2009
- cereal grain;
- feed hygiene;
- Lactobacillus panis;
- Lactobacillus plantarum;
- microbial population;
- Pichia fermentans;
- starter culture;
- wet wheat distillers’ grain
Aims: Investigating the influence of an added starter culture on the properties of fermented liquid pig feed.
Methods and Results: Diets of cereal grain blended with wet wheat distillers’ grain that were either not inoculated (WWDG), inoculated with a silage starter culture at start (WWDGsc1) or at start and at each backslopping (replacement of 80% the content with fresh mixture, simulating feed outtake, WWDGsc5) were fermented for 5 days, followed by 5 days of daily backslopping. Numbers of undesirable micro-organisms (enterobacteria, moulds) were reduced in all fermentations; particularly enterobacteria in the starter culture inoculated diets. Lactobacillus plantarum present in the starter culture became dominant in diets WWDGsc1 and WWDGsc5. However, Lactobacillus panis that was dominating WWDG was also abundant in WWDGsc1 and WWDGsc5. Yeast populations were not influenced by the starter culture, with Pichia fermentans dominating all fermentations. All diets had similar chemical characteristics with the exception of a significant increase of all tested organic acids in WWDGsc5.
Conclusions: The addition of a starter culture influences the bacterial population in fermented liquid feed, but there is also a strong impact of the flora already present in the feed ingredients. The yeast population is not influenced by adding a lactic acid bacteria (LAB) starter culture. A consortium of LAB and yeast strains adapted to the fermentation should be used as starter culture.
Significance and Impact of the Study: The results suggest that it is possible to influence the current unpredictable and spontaneous process of feed fermentation when appropriate starter cultures are used. For this purpose, LAB and yeasts with desirable characteristics should be isolated.