Supplementary Figure S1 - Timeline experimental protocol - JDS19932

Supplementary Figure S1. Timeline of the experimental protocol per batch of calves (2 batches, 24 calves each). For each treatment (6 calves per treatment), the adaptation period ranged from 6 to 9 weeks for pair 1 to 3 (i.e., paired according to BW). The second batch of calves had a higher BW from the start, therefore having a shorter adaptation period ranging from 5 to 8 weeks. The adaptation period was followed by 7 days in climate respiration chambers (pair-housed) to measure the recovery of 13C tracers in breath after intravenous administration of [13C]sodium bicarbonate and oral administration of [1-13C]octanoate and bacterial protein, as detailed for pair 1. Subsequently, calves were fitted with harnesses to which plastic bags were attached and housed individually in a pen for 7 days, to determine the fecal excretion curves of 3 orally administrated indigestible markers (i.e., Cr-NDF, Yb2O3, and Co-EDTA), as detailed for pair 3.