Ileum mucosal dry mass (A), protein (B), and DNA (C) in rats maintained with PN+GLP-2 for 7 days as follows: PN alone, casein, A (hydrolyzed soy/collagen), B (whey protein concentrate, WPC), C (hydrolyzed WPC+casein), BC, and ABC. Values are expressed as means ± SE; n = 6. Means with different letter superscripts are significantly different (P < 0.05). The right panel shows the combined effects of the four whey diets compared with casein, soy, and PN+GLP-2 alone.