Maintaining the barrier function of the intestine is important to maintaining weaned pigs’ health and productivity. It’s been found that weaning age affects the pig’s intestinal permeability, and the differences persist five weeks after weaning.

Properly functioning intestinal tissue acts as a selective barrier to allow nutrients in and to keep pathogens out. Loss of this barrier function increases the pigs’ susceptibility to intestinal infections and increases the energy needed to mount an immune response. 

Stress reduces the intestine’s barrier function; however, the mechanism by which this occurs is unclear. This is of particular importance to newly weaned pigs because the weaning process causes both physical and psychological stress. Also, disturbances that occur while the intestine is still developing have long-lasting consequences.

Recent work at North Carolina State University College of Veterinary Medicine by Adam Moeser, DVM, and his coworkers, examined weaning-age impact on intestinal barrier function, particularly in the pig jejunum. Pigs were weaned at different ages — 15, 18, 21, 23 and 28 days — and jejunal tissues were then harvested from 35-day-old pigs. The researchers concluded that increasing weaning age has the potential to improve lifetime intestinal health.

Specifically, the study showed a clear effect of older weaning age decreasing intestinal permeability. What’s more, the impact was still apparent more than five weeks after weaning. This suggests that just a few days difference in weaning age can have effects on pigs’ intestinal health throughout the nursery phase.

Moeser and his research group also identified a potential mechanism for degradation of barrier function seen with earlier weaning ages. With more research, Moeser hopes to identify ways to reduce this effect.