Figure 1.

True protein digestibility^a of a basal feed (∼15% crude protein dry matter) in Wistar rats as affected by either drinking water (control) or a 30% fructose water solution for 10 weeks. ^aTrue protein digestibility (%) = {[TNf – (FN – TEp)]/TNf} × 100, where TNf is total nitrogen from feeds (dietary nitrogen), FN is fecal nitrogen, and TEp is the total metabolic/endogenous nitrogen found in feces from a rat fed a protein-free diet.²⁵ The pair of means with asterisks is significantly different in Student-t tests: ***p < 0.001.