Most diets for weanling pigs contain highly digestible plant and animal proteins, but there is an increasing trend to include more fibrous co-products in diets for pigs due to reduced diet costs. However, feeding diets to nursery pigs with high concentration of dietary fiber may reduce nutrient digestibility, induce intestinal inflammation, and subsequently depress growth performance. Addition of 100 to 200 mg/kg of Cu from Cu hydroxychloride (IntelliBond C^II; Micronutrients USA LLC; Indianapolis, IN) to diets improves feed efficiency and reduces post weaning diarrhea in pigs. However, there are at this point no data to demonstrate the effect of Cu hydroxychloride on intestinal barrier integrity of pigs fed low-fiber or high-fiber diets, and it is not known if Cu hydroxychloride influences immune responses of pigs. Therefore, 2 experiments were conducted to test the hypothesis that inclusion of 150 mg/kg of Cu from Cu hydroxychloride reduces intestinal permeability and subsequently improves growth performance of pigs fed diets without or with high concentration of dietary fiber.