“…13 C]-glucose was determined by GC-MS (QP2010, coupled with GC 2010; Shimadzu, Duisburg, Germany) as recently described (Hammon et al, 2008;Steinhoff-Wagner et al, 2011). Whole blood in potassium-EDTA tubes collected before and at regular intervals between 10 to 240 min after start of tracer infusion was used to isolate CO 2 , to measure its 13 C/ 12 C Concentrate Universal 18/3 (Vollkraft Mischfutterwerke GmbH) consisted of (g/kg of DM) 200-400 g of cereals (triticale, rye, wheat, barley), <250 g of rapeseed expeller, malt germs, wheat gluten, wheat bran, peeled oat-bran, beet pulp chips, molasses, glycerin, calcium (0.19 mol; 7.5 g), phosphorus (0.18 mol; 5.5 g), sodium (0.09 mol; 2 g), retinol (9.66 μmol; 2.4 mg), β-carotene (8.95 μmol; 4.8 mg), 25-OHvitamin D 3 (0.05 μmol; 22.5 μg).…”