Our objective was to characterize small intestinal (SI) adaptation in a novel piglet model. Piglets (n = 27, 12 d old) were randomized to 1) 80% SI resection with total parenteral nutrition (TPN) feeding (R‐TPN), 2) 80% SI resection with TPN + enteral feeding (R‐EN) or 3) sham SI transection with TPN + enteral feeding (Sham‐EN). In the R pigs, the distal 100 cm of ileum (residual SI) and 30 cm of proximal SI was left intact. All pigs received TPN after surgery. R‐EN and Sham‐EN piglets also received continuous gastric infusions of elemental diet starting on d 3 (40:60 TPN:EN). Piglets were kept for 4, 6 or 10 d post‐surgery. The weights of residual SI and mucosa were greater in R‐EN compared to other pigs at 4, 6 and 10 d. By d 10, weight per length of residual SI in R‐EN animals was more than 25% greater than other groups; R‐EN mucosal mass was 65% higher. Rate of residual SI length growth in the R‐TPN and R‐EN was twice that of the Sham‐EN, indicating massive adaptation responsive to enteral feeding. A rapid decline in plasma arginine and glutamate occurred in enterally fed groups compared to R‐TPN pigs (p<0.05). Ornithine decarboxylase activity in mucosa of R‐EN pigs at d 10 was 35% higher than Sham‐EN and 60% higher than R‐TPN. Route of amino acid delivery may have affected whole body availability, as the gut may have extracted significant amounts of enteral arginine and glutamate to support intestinal adaptation growth. (SickKids Foundation)