Changes in diarrhea, nutrients apparent digestibility, digestive enzyme activities of weaned piglets in response to chitosan-zinc chelate.

A total of 120 weanling barrows weighing 6.11 ± 0.20 kg were randomly allotted to four treatments with three replications (i.e. pen) of ten piglets per replicate. Pigs were received corn-soybean basal diet (control) or the same basal diet supplemented with the following sources of zinc: (i) 100 mg/kg of Zn as ZnSO4 ; (ii) 100 mg/kg of Zn as chitosan-Zn chelate (CS-Zn); and (iii) 100 mg/kg of Zn as ZnSO4 mixed with chitosan (CS + ZnSO4 ). The results showed that CS-Zn could highly improve average daily gain and average daily feed intake than those of ZnSO4 or CS+ ZnSO4 (P < 0.05). The pigs fed dietary CS-Zn had lower diarrhea incidence and higher apparent digestibility of crude protein than those of the pigs fed dietary ZnSO4 (P < 0.05). The protease activities in duodenal content of the pigs receiving CS-Zn diets was higher than that of the pigs fed dietary ZnSO4 or CS + ZnSO4 (P < 0.05). The amylase activity in duodenal content of the pigs fed dietary CS-Zn was higher than that of the pigs receiving ZnSO4 diets or basal diets (P < 0.05). These results indicated that dietary CS-Zn showed different bioactivities from ZnSO4 or CS + ZnSO4 in reducing the incidence of diarrhea, improving activities of digestive enzymes and growth performance of weaned pigs.