1. UMR
1213 Herbivores, INRA, F-63122 Saint-Genès Champanelle, France
2. VetAgro
Sup, UMR 1213 Herbivores, Clermont Université, B.P. 10448, F-63000 Clermont-Ferrand, France
3. Elucidation
of Biosynthesis by Isotopic Spectrometry Group, CEISAM, UMR6230, CNRS−University of Nantes, B.P. 92208, F-44322 Nantes, France