In conclusion, the data generated by this study demonstrated that a
diet supplemented with 300 mg/kg COS or 50 mg/kg chlortetracycline
in weaned piglets decreased feed conversion ratio, the villus width,
the crypt depth and TLR4mRNAexpressions, but increased villus length,
villus length/crypt depth and GCs. There was no observed effect on
Claudin-1 mRNA expression. Furthermore, COS had a better effect on
IELs than chlortetracycline, and COS showed positive activity but chlortetracycline
caused a negative effect on occludin and no significant effect on sIgA protein expression. This illustrates that COS and the antibiotic
have similar effects on promoting animal growth and reducing intestinal
inflammation, but have different effects on animal intestinal
mucosal barrier function. To sum up, this study shows that chitosan
has the potential to replace chlortetracycline as a feed additive for pigs.