Effects Of Nano-ceria On Activity And Gene Expression Of Digestive Enzyme Of Hens

A feeding study was performed to investigate effect of nano-ceria on activity and gene expression of digestive enzyme of hens, and the mechanism of their influence on digestive enzyme was discussed. Three hundred eighty four 26-week old healthy commercial hens were selected and allotted randomly to four treatments, each treatment was divided into eight replicates comprising twelve hens each. The basal diet was corn-soybean meal. The treatment diets were basal diet with 0 mg/kg (â… ), 30 mg/kg (â…¡), 60 mg/kg (â…¢) and 90mg/kg (â…£) nano-ceria. The whole period consisted of a one week pretest and a six weeks test. The result showed that:1.Effect of nano-ceria on intestinal digestive enzyme activity:The nano-ceria supplementation had effect on activity of amylase and trypsin, but no significant effect on lipase activity (P>0.05).In the comparison with the control group, groupâ…¡(30mg/kg) tended to improve amylase activity, but the difference was not significant (P>0.05).Groupâ…¢(60mg/kg) significantly decreased activity of amylase and trypsin (P<0.05).Groupâ…£(90mg/kg) significantly decreased amylase activity (P<0.01) and trypsin activity (P<0.05).2.Effect of nano-ceria on pancreatic digestive enzyme activity: The nano-ceria supplementation to the diet had an effect on activity of amylase, lipase and trypsin. In the comparison with the control group, groupâ…¡(30mg/kg) tended to improve amylase activity and trypsin activity, while groupâ…¢(60mg/kg) tended to decrease them, but the difference was not significant (P>0.05).Groupâ…¢(60mg/kg) significantly improved lipase activity (P<0.05) and decreased amylase activity (P<0.05).3.Effect of nano-ceria on gene expression of pancreatic digestive enzyme:The nano-ceria supplementation had effect on mRNA level of digestive enzyme gene. In the comparison with the control group, groupâ…¡(30mg/kg) up-regulated mRNA level of trypsinâ…¡gene (P<0.01), pancreatic amylase gene and trypsinâ… gene (p<0.05), but there was no significant in mRNA level of pancreatic lipase(p>0.05). Groupâ…¢(60mg/kg) up-regulated mRNA level of pancreatic lipase,but down-regulated mRNA level of trypsinâ…¡gene (P<0.01) and pancreatic amylase gene (P<0.05). Groupâ…£(90mg/kg) down-regulated mRNA level of trypsinâ…¡gene (P<0.01) and pancreatic amylase gene (P<0.05),but had no influence on mRNA level of pancreatic lipase gene (P>0.05).Furthermore, the chicken trypsin family can be divided into two member subfamilies, trypsinâ… subfamily and trypsinâ…¡subfamily.In each experimental group,mRNA level of trypsinâ…¡gene of was 6.0,6.0,4.5 and 5.2 times higher than that of trypsinâ… gene, respectively.Therefore, trypsin activity depended on mRNA level of trypsinâ…¡geneThe result indicated the supplementation of nano-ceria to the diet would regulate trypsin gene expression at transcriptional or posttranscriptional level, furthermore, affect synthesis and secretion of trypsion.