Effects of Clostridium butyricum or in combination with Bacillus licheniformis on the growth performance, blood indexes, and intestinal barrier function of weanling piglets

Abstract

This study was conducted to evaluate the effects of Clostridium butyricum or in combination with Bacillus licheniformis on the growth performance, blood characteristics, and intestinal barrier function of weanling piglets. A total of 150 piglets weaned at 23 ± 2 d were assigned to 5 treatments with 3 pens per treatment and 10 pigs per pen. Dietary treatments were as follow: basal diet + antibiotics (100 mg olaquindox/kg, 20 mg colistin sulfate/kg, and 50 mg kitasamycin/kg) + 2250 mg Zn from ZnO/kg (Control A); basal diet + antibiotics + 1125 mg Zn from ZnO/kg (Control B); basal diet + 1125 mg Zn from ZnO/kg + 109 cfu/kg of Bacillus licheniformis (BL); basal diet + 1125 mg Zn from ZnO/kg + 108 cfu/kg of Clostridium butyricum (CB); and basal diet + 1125 mg Zn from ZnO/kg + 108 cfu/kg of Clostridium butyricum + 109 cfu/kg of Bacillus licheniformis (CB-BL). The results indicated that the piglets fed the control B diet exhibited a decrease in growth performance, and an elevated incidence of diarrhea compared with the piglets fed the control A diet (P < 0.05). Meanwhile, we found that the CB and CB-BL treatments exhibited increased growth performances, and decreased incidences of diarrhea compared to the control B treatment (P < 0.05). Serum concentrations of total antioxidant capacity, superoxide dismutase, glutathione peroxidase, immunoglobulin G, immunoglobulin A, and complement protein C3 were greater in the CB treatment and CB-BL treatment compared to control B treatment (P < 0.05), while the pro-inflammatory cytokines interleukin-6, tumour necrosis factor-α, and interferon-γ were reduced (P < 0.05). However, statistical differences were not found in these blood characteristics between control A treatment and CB treatment. Piglets fed the CB diet exhibited a greater villus height:crypt depth in the duodenum and ileum compared to the piglets in the other 4 treatments (P < 0.05). Moreover, the CB-BL treatment exhibited greater mRNA expressions of tight junction proteins (i.e., claudin-1, occludin, zonula occludens protein-1, and zonula occludens protein-2) in the small intestine compared to control B treatment (P < 0.05). The mRNA expressions of zonula occludens protein-1 and zonula occludens protein-2 in both the duodenum and ileum of the piglets fed CB diet were particularly greater than those in control A treatment (P < 0.05). These results indicated that the application of Clostridium butyricum alone or in combination with Bacillus licheniformis provided a potential alternative strategy for reducing the concentration of antibiotics and ZnO in the diets of weanling piglets.