Effects of dietary supplementation with epidermal growth factor on nutrient digestibility, intestinal development and expression of nutrient transporters in early-weaned piglets

The abnormalities in intestinal morphology and digestive function during weaning are associated with the loss of milk-borne growth factors. Epidermal growth factor (EGF) has been shown to stimulate the growth of animals. This study was to determine the effect of dietary EGF on nutrient digestibility, intestinal development and the expression of genes encoding nutrient transporters in weaned piglets. Forty-two piglets were weaned at 21days and assigned to one of three treatment groups: (1) basal diet (control), (2) basal diet+200 mu g/kg EGF or (3) basal diet+400 mu g/kg EGF. Each treatment consisted of 14 replicates, and seven piglets from each treatment were sampled on day 7 and 14. The EGF supplementation significantly elevated (p<0.05) the coefficients of total tract apparent digestibility of crude protein, calcium and phosphorus, but tended to decrease sucrase activity (p<0.10) than the control group. At day 7 post-weaning, animals receiving EGF diets showed a tendency (p<0.10) towards greater ileal villus height (VH), jejunal crypt depth (CD) and duodenal VH:CD when compared with the control group. Moreover, the mRNA levels of glucose transporter 2 (Slc2a2), neutral amino acid transporter (Slc6a19) and calbindin D9k (S100G) tended to be higher (p<0.10) for EGF groups than the control group. By day 14, EGF supplementation markedly enhanced (p<0.05) the VH, CD and VH:CD in the jejunum compared to the control group. This addition also up-regulated (p<0.05) the mRNA level and the protein abundance of peptide transporter 1 than the control group. These findings demonstrated that dietary EGF beneficially enhanced nutrient digestibility, improved intestinal development and increased the mRNA expression of nutrient transporters in weaned piglets.