Effects Of Chitosan On Nutrient Metabolism And Intestine Related Indexes In Breeding Layers

The research was conducted to estimate the effects of different levels of chitosan on nutrient metabolism, digestive enzyme activity, intestine morphology and gut microflora. A total of 450 breeding layers were selected and divided randomly to 5 dietary treatments, and each treatment was divided into 6 replicates with 15 hens included. The dietary treatments included basal diet and other 4 diets with chitosan implementation of 250,500,1000 and 2000 mg/kg, respectively. Feeding trial lasted for a total of 56 days and the preliminary trial period was 1 week. Feed and water were provided ad libitum during the entire experimental period. All the experimental birds were under the same conditions except experimental diets. The results showed:(1) Dietary supplementation of chitosan quadratically improved the apparent metabolic rate of dry matter (P=0.032), crude protein (P=0.001), calcium (P=0.003) and phosphor (P=0.027) on day 56, and quadratically reduced the apparent metabolic rate of EE(P=0.050).(2) Dieary supplementation of chitosan quadratically increased (P=0.019) trypsase activity in duodenum and reduced (P=0.008) lipase activity in jejunum on day 28, and quadratically increased trypsase activity in duodenum (P=0.059) and chymotrypsin activity in jejunum (P=0.009), but reduced linearly (P=0.021) or quadratically (P=0.001) lipase activity in jejunum, and reduced quadratically (P=0.007) lipase activity in ileum on day 56. There is no significant dosage effect for amylase activity.(3) Dietary supplementation of chitosan qudratically increased villous height of duodenum on day 28 (P=0.008) and 56 (P=0.021). On day 28, dietary supplementation of chitosan linearly (P=0.032) increased the ratio of villous height to crypt depth (VH/CD). On day 56, dietary supplementation of chitosan quadratically increased VH/CD of duodenum (P=0.003) and jejunum (P=0.012). However, there was no significant dosage effect in crypt depth.(4) Dietary supplementation of chitosan increased quadratically (P=0.035) lactobacillus in cecum on day 56 and inhibited linearly (P=0.036) or quadratically (P=0.047) the proliferation of E. coli (P=0.036, P=0.047) in cecum on day 28, In addition, dietary supplementation of chitosan quadratically increased the ratio of lactobacillus to E. coli on day 28 (P=0.035) and 56 (P=0.002).In conclusion, the addition of chitosan in dietary could improve the trypsase and chymotrypsin activity, enhanced the apparent metabolism ratio of dry matter, crude protein, calcium and phosphor, reduced lipase activity, inhibited fat absorption, improved mucosal morphology and gut microflora. These may be important causes to improve the production performance of laying hens.