Physiological Characteristics of Piglets: 
Mouth: physical digestion (teeth) Chemical digestion (salivary glands)
Stomach: physical digestion (peristalsis) Chemical digestion (pepsin)
Small bowel: Chemical digestion (pancreatic mucosal secretase)
Colon: Microbial digestion (volatile fatty acids)
The colon absorbs the products of bacterial fermentation, mainly SCFAS, which typically account for up to 10% of the total dietary energy intake, and certain combinations of bacteria can provide more energy to the host
Main factors affecting intestinal health of pigs in farming:   
Pathogenic factors: epidemic diarrhea, infectious gastroenteritis, rotavirus and pseudorabies, chronic swine fever, Escherichia coli, salmonellosis, pig dysentery, coccidiosis, etc. 
Feed factors: long-term feeding moldy and deteriorated feed, water contamination, ingestion of pesticides, feed nutritional composition, nutritional imbalance, digestive disorder, nutritional metabolic disease, etc    
Environmental factors: soil and water polluted by heavy metals air quality low temperature sudden change high heat and cold lack of ventilation measures and other
management factors: daily management errors, emergency, piglet health care stress, transfer group, transport, feeding density and other 
Application of Clostridium butyricum in piglets: 
Clostridium butyricum can improve the production performance, effectively relieve diarrhea piglets Effective guarantee the intestinal villi form, maintaining the mechanical barrier Ease the lipopolysaccharide of small intestinal morphology damage Increase the hindgut volatile fatty acid level, thus ensuring piglets intestinal villi morphological structure Improve piglets intestinal tight junction protein expression and consolidate the intestinal barrier function  
Clostridium butyricum can regulate the cell proliferation level, promote the repair of intestinal barrier function and improve the abundance of beneficial bacteria in intestinal tract of piglets, and its probiotic metabolites can improve the immune level of piglets