Intrauterine Growth Restriction and Its Impact on Intestinal Morphophysiology Throughout Postnatal Development in Pigs

Intrauterine growth restriction (IUGR) compromises fetal development, leading to low birth weight, and predisposes to gastrointestinal disorders. Pigs that suffered IUGR present poor postnatal development, resulting in great economic losses to the industry. The small intestine may be involved with their growth commitment, but studies investigating this issue are still limited. Thus, the present study aimed to investigate small intestine morphofunctional alterations in IUGR pigs throughout the production phases (birth to 150 days). IUGR pigs presented lower body weight from birth to the finishing phase (P<0.05). Although histomorphometrical parameters were not affected during the pre-weaning period, their commitment was observed specifically in the duodenum of the IUGR group at older ages (P<0.05). The most detrimental effects on the small intestine, such as highest duodenum crypts’ depth, lowest villus height:crypt depth ratio and absorptive area, increased apoptosis and lower proliferation of the duodenum epithelium were noticed at 70 days of age (P<0.05). Additionally, IUGR pigs presented the lowest chymotrypsin and amylase activities at 70 and 150 days of age, respectively (P<0.05). These findings showed intestinal disturbances in IUGR pigs throughout the different production phases, demonstrating that poor performance is a consequence of intestinal damage mainly at the grower period.