Adopt a multifactorial approach on piglets weaning stress
Early weaning stress can impact future performance
In nature, weaning in pigs is a gradual process that occurs at about 3 months of age and represent the shift from the piglet’s reliance on sow’s milk to other food sources. In modern production systems, weaning is one of the most stressful events in the pig’s life where they face social and physiological changes including abrupt change in diet, maternal and littermate’s separation, and the establishment of a new social hierarchy. These early life stressors can contribute to intestinal and immune system dysfunctions that may have both short and long-term effects on reduced pig health, feed intake, and growth, particularly during the first weeks after weaning. Besides these stressful weaning process during the first weeks of life, gastric hydrochloric acid formation and pancreatic enzyme secretions is poor or not fully activated yet in the digestive tract. Given the link between early life stress and gastrointestinal diseases, it has been shown that early weaning stress can profoundly alter physiology responses by disrupting the homeostasis in the composition of the gut microbiome. The disruption of this symbiotic relationship, named dysbiosis, has been associated with alterations in the intestinal mucosal barrier functions, such as, upregulate expression of proinflammatory cytokines that affect intestinal barrier integrity, and decreased mRNA expression of tight junction proteins. Consequently, the reduction in trans-epithelial electrical resistance and increased intestinal permeability facilitates the transmigration of luminal antigens and toxins across the “leaky gut” into sub-epithelial tissues, lamina propria, and underlying blood vessels, inciting inflammatory processes and systemic disease. The compromised barrier function can aggravate post weaning diarrheal diseases such as enterotoxigenic E. coli, rotavirus, and Clostridium difficile, leading to changes in intestinal morphology associated with high mortality and poor performance.