1. Laboratory of Food Chemistry and Biochemistry, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, BE-3001 Leuven, Belgium.
2. Corresponding author. Phone: +32 (0)16321917. Fax: +32 (0)16321997. E-mail: christophe.courtin@biw.kuleuven.be
3. K.U. Leuven Research & Development, Minderbroedersstraat 8A, BE-3000 Leuven, Belgium.
4. Laboratory of Physiology and Immunology of Domestic Animals, Katholieke Universiteit Leuven, Kasteelpark Arenberg 30, BE-3001 Leuven, Belgium.
5. Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, BE-9000 Gent, Belgium.
6. Instituut voor Landbouw- en Visserijonderzoek (ILVO), Animal Sciences Unit Scheldeweg 68, BE-9090, Melle, Belgium.