Effects of chitosan as growth promoter on diarrhea, nutrient apparent digestibility, fecal microbiota and immune response in weaned piglets

The efficacy of chitosan (CS) to enhance performance, immune response and reduce diarrhea rate in weaned piglets was evaluated. A total of 24 piglets were individually housed in pens. Animals received 1 of 2 dietary treatments: a control diet to which 500 mg/kg CS was added. The experiment lasted for 14 days. Body weight was recorded and daily feed intake was calculated. Fecal consistency was monitored throughout the experiment. At the end of the trial, blood and feces samples were collected to determine immune parameters, nutrient apparent digestibility and fecal microbial populations. Results showed that CS improved daily weight gain (p < .01) and feed conversion ratio (p < .01) during the overall period. Fecal score values were improved by CS compared to the control diet (p < .001) and showing decreased values in the entire period. The CS addition decreased E.coli (p = .02), Salmonella (p < .01) and Staphylococcus aureus (p < .01) counts, and increased the ratio of Lactobacillus to E.coli (p = .04) in the feces. Serum IL-2 (p = .02) and IgG (p = .07) levels were increased and serum cortisol (p < .05) was lowered in CS group compared to control group. The results suggested that the use of CS could improve performance and immune response of weaned piglets by promoting nutrient apparent digestibility, regulating the fecal microbiota as well as increasing serum IL-2 and IgG concentrations and decreasing serum cortisol level.