Developmental differences in the effect of natural feeding on early enteric mucosal growth of guinea pigs

In contrast to observations in other species, neither enteric mucosal weight, protein content, nor DNA content of either the suckled or artificially fed guinea pig changes over the first 24 h following term birth. In guinea pigs delivered 5 days prematurely, however, statistically significant increases in proximal enteric mucosal mass (38%), protein content (51%), and DNA content (35%) occur in suckled animals over the first 24 h of life but not in artificially fed animals. These observations illustrate that the enteric mucosal hyperplasia secondary to natural feeding, quantitatively and temporally, is species-specific and suggest that this effect is manifested only during a finite period of intestinal development. They raise doubts, therefore, concerning the importance of early enteric mucosal hyperplasia in adaptation of all species to extrauterine life.