Influence of wean age and disease challenge on progeny lifetime performance

Weaning can be one of the most stressful occurrences for the pig, said Dr. David Rosero with The Hanor Company in Franklin, Ken. The pigs have abrupt maternal separation, a different food source, co-mingling, pathogens, and other stressors. Enzyme activity also is reduced.

"Any stress that happens early in life (at weaning) has long-term consequences from the standpoint of disease risk and severity," Rosero said.

If pigs are weaned earlier, the intestinal barrier is disrupted. Rosero reported that early-weaned pigs had higher intestinal permeability compared to those that were weaned later and the long-term consequences were amplified.

"Pigs were compromised at 16 or 18 days when they were exposed to an E. coli challenge, but at 10 days old, we didn't see a dramatic increase in their intestinal permeability," Rosero said. "On immune response, at 16 and 18 days of age, they're not able to respond to a pathogen challenge but when they were weaned at 20 days of age, they had a much higher immune response to an E. coli challenge.

"Response to weaning is immediate and acute, and we've learned that it has long-term consequences," Rosero said.