Skatole production in the pig gut

PhD defence, Monday 20 February 2017. Xiaoqiong Li.

2017.02.20 | Steffi Hjerrild Iversen

Xiaoqiong Li

During her studies, Xiaoqiong Li researched skatole production in the pig gut. Skatole, produced by anaerobic microbial degradation of L-tryptophan in the hindgut, is the main compound responsible for boar taint, an off-odor and off-flavor taint released upon heating meat from some entire male pigs. Surgical castration is a common practice to prevent boar taint. However, this practice is painful and therefore problematic from a welfare point of view.

With an EU declaration aiming at ending surgical castration by January 2018, it becomes urgent to find feasible alternatives to prevent boar taint. Xiaoqiong Li studied the skatole-producing bacteria inhabiting the hindgut of pigs, their metabolism and genome, and quantified their abundance in the hindgut, and further explored the mode of action behind the reducing effect of dietary fiber (chicory roots) on skatole production. These research findings indicated that skatole production is seemed to be limited to one bacterium, Olsenella scatoligenes, but that the reducing effect of fermentable fiber on skatole production is not due to a reduction of skatole-producing bacteria or increased butyric acid production, but probably to a higher incorporation of L-tryptophan into bacterial biomass.

The PhD degree was completed at the Department of Animal Science, Science and Technology, Aarhus University.

This résumé was prepared by the PhD student.

Monday 20 February 2017 at 12.00
 Auditorium, Blichers Allé 20, Aarhus University, Foulum, 8830 Tjele.
Title of dissertation:
 Skatole production in the pig gut
Contact information:
 Xiaoqiong Li,, tel.: +45 31858383
Members of the assessment committee:

Professor Jan Erik Lindberg, Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Sweden.
Professor Ulrike Weiler, Institute of Animal Husbandry and Animal Breeding, University of Hohenheim, Germany
Associated Professor Jan Værum Nørgaard (chair), Department of Animal Science, Aarhus University
Main supervisor:
Senior Scientist Nuria Canibe, Department of Animal Science, Foulum, Aarhus University, Denmark.
Senior Scientist Emeritus, Bent Borg Jensen, Department of Animal Science, Foulum, Aarhus University, Denmark.
 The PhD dissertation will be defended in English

The defence is public.
The dissertation is available for reading at the Graduate School of Science and Technology/GSST, Ny Munkegade 120, building 1520, rooms 128-134, 8000 Aarhus C.

PhD defence
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Revised 24.02.2017