Figure 2.

Evolution of the concentration of total dietary protein (TDP)^a at the different stages of the in vivo digestion of basal feed (∼15% crude protein dry matter) as affected by either drinking water (control) or a 30% fructose water solution for 10 weeks. ^aTotal dietary protein (TDP, g/100 g digests) was calculated in feeds, luminal material of each compartment of the GIT, and feces as follows: TDP (g)= [(WSN – NPN) – Ep] × 6.25; WSN is water-soluble nitrogen, NPN is nonprotein nitrogen, and Ep is the metabolic/endogenous nitrogen.^24,25 Ep refers to nitrogen-containing biomolecules (i.e., proteins, peptides, etc.) secreted at each stage of the GIT of an animal receiving a protein-free diet. Results are presented in dry matter, and hence, the moisture of each sample was also taken into account.