Efficacy of dietary chitosan on growth performance, haematological parameters and gut function in broilers

Abstract

Percentages of antimicrobial resistance to Salmonella and Escherichia coli in poultry products were high in Thailand, thus, alternative to antibiotic growth promoter is required. The objective of this experiment aimed to examine the effect of dietary chitosan in broilers on blood and intestinal changes. Total of 392, day-old male Ross 308 broilers were allotted into four groups. Broilers in the control group (group 1) received commercial corn-soybean meal-based basal diet. Chicks in group 2 received basal diet supplemented with 200 ppm amoxicillin. Chitosan was added into the basal diet at 1 and 2 g/kg in groups 3 and 4, respectively. Data on growth performance as well as blood and digesta samples were collected on d 21 and 39. The results showed that 2 g/kg dietary chitosan significantly improved feed conversion ratio (FCR) during d 22-39 and 1-39 (p < .05). This level of chitosan also increased the ratio of villus height (VH) and crypt depth (CD) (p < .05) while decreased the CD (p < .05). The supplementation of 1 and 2 g/kg chitosan in diet tended to reduce the ammonia-nitrogen in colonic digesta. Furthermore, both levels of chitosan enhanced number of Bacillus spp. while decreased number of E. coli (p < .001) leading to increased ratio of Lactobacillus and E. coli (p < .001). There were no significant effects on the heterophil (H): lymphocyte (L) ratio and coefficient of apparent ileal digestibility. In conclusion, the supplementation of 2 g/kg chitosan in broiler diets could be used as an alternative additive to antibiotic with its improvement on gut function.