Dietary chitosan-Cu chelate affects growth performance and small intestinal morphology and apoptosis in weaned piglets

The effects of dietary chitosan-copper chelate (CS-Cu) on growth performance, diarrhea, intestinal morphology and epithelial cell apoptosis in weaned piglets was investigated. One hundred and sixty Duroc × Landrace × Yorkshire weanling barrows with an average body weight of 7.75 kg were randomly assigned to one of the following dietary treatments: (1) control, (2) 100 mg Cu/kg diet from CuSO4, (3) 100 mg Cu/kg diet from CuSO4 mixed with chitosan (CuSO4+CS), (4) 100 mg Cu/kg diet from CS-Cu. The feeding trial lasted for 30 days. The results showed that the pigs receiving a diet containing CS-Cu had higher average daily gain and lower diarrhea incidence than the pigs receiving dietary CuSO4 and CuSO4+CS. Villus height and the ratio of villus height/crypt depth in duodenum, jejunum, and ileum were higher and crypt depth was lower in CS-Cu treated pigs than in pigs fed dietary CuSO4 or CuSO4+CS. An apparent decrease of ileal epithelial cell apoptosis in pigs fed CS-Cu diet was found. The activities of antioxidant enzymes were higher in pigs fed dietary CS-Cu than in those fed other diets. The results indicated that dietary CS-Cu showed better biological and physiological function in improving small intestinal morphology and reducing diarrhea incidence.