Rezaei Koochacksaraei R - Department of Animal and Poultry Nutrition, Faculty of Animal Science, Gorgan University of Agricultural Sciences & Natural Resources, Gorgan, Iran
Dastar B - Department of Animal and Poultry Nutrition, Faculty of Animal Science, Gorgan University of Agricultural Sciences & Natural Resources, Gorgan, Iran
Samadi F - Department of Animal and Poultry Physiology, Faculty of Animal Science, Gorgan University of Agricultural Sciences & Natural Resources, Gorgan, Iran
Ebrahimi P - Department of Chemistry, Faculty of Sciences, Golestan University, Gorgan, Iran

Chitin is the most abundant natural biopolymer that can be converted to chitosan, which has various biomedical applications. This study was conducted to investigate the antioxidant activity of chitosan extracted from shrimp shells on body weight of broiler chickens. The study comprised three experiments. In experiment 1, shrimp (Penaeus merguiensis) shells were demineralized using HCL (1N), deproteinized using NaOH (1N), decolorized using acetone, and deacetylated using 50% NaOH. The antioxidant potencies of chitosan and vitamin C were compared by their abilities to scavenge 1, 1-diphenyl-2- picrylhydrazyl (DPPH) free radicals. The DPPH free radical scavenging activity of chitosan at varying concentrations (1-20 mg/ml) ranged between 34.59 and 87.11%, whereas that of 1 mg/ml of vitamin C was 91.1%. In experiment 2, six dietary treatments containing varying concentrations of chitosan (0, 0.125, 0. 25, 0.5, 1, and 2 g/kg) were allocated randomly to 60 male broiler chicks from 10 to 42 days of age. Chitosan at varying concentrations had no significant effect on the body weight, but it significantly decreased the MDA level in breast meat (p<0.05). In experiment 3, a total of 20 male broiler chickens were divided into two groups (n=10) and were fed a corn-soybean basal diet with or without chitosan for 42 days. On days 35 and 38, five chickens from each group were treated with carbon tetrachloride (CCL4) at 1 mL/kg body weight to induce oxidative stress. Administration of CCL4 significantly decreased body weight and increased AST and ALT activities, which are indicators of liver damage, on day 42, whereas chitosan improved and normalized body weight and enzyme activity (p<0.05). The results suggested that chitosan extracted from shrimp shells exhibits antioxidant effects by increasing the shelf life of the meat and normalizing the body weight of the broilers as well as serum AST and ALT enzyme activities.

Chitosan, Antioxidant, Shrimp shells, Broiler chickens