The Three-Week-Old Piglet as a Model Animal for Studying Protein Digestion in Human Infants

The piglet was evaluated as a model animal for studying the digestion of high-quality proteins in human infants. Three-week-old male piglets (n = 6) and 3-month-old male human infants (n = 6) were fed a bovine-milk-based formula over a 17-day experimental period comprising 7 days' adaptation followed by a 10-day fecal collection period. The piglets and infants were given 345-g liquid formula/kg body weight/day and 170-g liquid formula/kg body weight/day, respectively, which equated to similar dry matter intakes per unit stomach volume (0.923 g dry matter/cm3/day). Both the piglets and infants were individually bottle-fed the reconstituted milk formula (12.2% dry matter) at similar meal frequencies. Small but statistically significant differences (p < 0.01) were found for the apparent fecal digestibility (mean +/- overall SE) of dietary dry matter (98.8 versus 97.4% +/- 0.13%), organic matter (99.0 versus 97.7% +/- 0.12%), and total nitrogen (97.5 versus 94.5% +/- 0.36%) between the piglets and infants. The fecal digestibilities for most of the amino acids were not significantly different (p > 0.05) between the species. The digestion of protein appeared to be similar in the two species. The study provides support for using the piglet as a model animal for studying protein digestion in human infants.