Attribution of Antioxidation of Quercetin in Vitro and Arbor Acre Broilers

The antioxidant effects of quercetin were studied in vitro and in vivo.In vitro,vitamin C was used as a positive control to evaluate the antioxidant capacity of quercetin in three aspects:scavenging free radicals,protecting biological macromolecules and the total reducing power.In vivo,a total of 240 AA broilers(1-day age)with similar body weight were randomly divided into four groups with six replicates in each group,and 10 broilers in each replicate.The four groups were fed with corn-soybean basal diet supplemented with 0.00%,0.02%,0.04%and 0.06%quercetin to study its effects on antioxidant indexes of AA broilers,and to explore the optimal dose of quercetin as a dietary additive.The results showed that quercetin scavenged superoxide anion,hydroxyl radical and 1,1-diphenyl-2-picrylhydrazyl(DPPH)in vitro,the scavenging effects of quercetin on O_(2)-and•OH first increased and then decreased with the increase of the concentrations(P<0.01),and its maximum scavenging effect was observed at concentrations of 40 and 300 mg·L^(-1).The scavenging effects of quercetin on DPPH was increased constantly with increasing concentrations.The scavenging effect of quercetin on three free radicals was DPPH>•OH>O_(2)-.The inhibition of vitelline lipoprotein peroxidation by quercetin was increased with increasing concentrations(P<0.01)and the inhibitory effect was higher than that of vitamin C.The inhibition of red blood cell hemolysis by quercetin was increased with increasing concentrations at 0.05-1.25 mg·L^(-1)(P<0.01);however,the inhibition tended to decrease when the concentration was too high(31.25 mg·L^(-1)),and the inhibitory effect was higher than that of vitamin C.The inhibition of mitochondrial expansion by quercetin was increased with increasing concentrations,according to the degree of mitochondrial expansion at 60 min,the integrity of mitochondria in the experimental groups was significantly higher than that in the model group(P<0.01).The total reducing power of quercetin was increased with increasing concentrations(P<0.01);however,the total reducing power was less than that of vitamin C.In vivo,malondialdehyde(MDA)and nitric oxide(NO)were significantly decreased with increasing quercetin(P<0.01).Quercetin supplementation had no effect on the content of lipid peroxidation(LPO)in livers(P>0.05);however,superoxide dismutase(SOD)activity was significantly increased,whereas glutathione peroxidase(GSH-Px)and catalase(CAT)activities were significantly decreased in livers with increasing quercetin(P<0.05).These results suggested that quercetin exhibited strong antioxidant effects in vitro and in vivo.

A comparative study to determine the effects of breed and feed restriction on glucose metabolism of chickens

The glucose metabolism of poultry draws wide attention as they have nearly twice the fasting blood glucose than that of mammals.To define the relationship between glucose metabolism and breed of chicken,the outcomes from different growth rate chickens showed that Arbor Acres(AA)broilers,a well-known fast-growing breed,had a lower fasting blood glucose concentration and glucose clearance rate when compared to Silky chickens,a Chinese traditional medicinal chicken with black skin and a slow growth rate.Moreover,AA broilers had a relatively slow rise in blood glucose in response to oral glucose solution than the Silky chickens on 21 and 42 d(P<0.05),which is probably attributed to downregulated expression of pancreatic insulin(INS),and upregulated transcription of phosphoenolpyruvate carboxy kinase 1(PCK1)and glucose transporter 2(GLUT2)in the liver of AA broilers(P<0.05).In response to feeding restriction from 7 to 21 d,both the fasting blood glucose and the response speed of AA broilers to oral glucose were increased on d 21(P<0.05),and the serum glucose concentrations after 3 weeks compensatory growth were improved by early feed restriction in AA broilers.Feed restriction could also upregulate the mRNA level of pancreatic INS on d 21 and 42,as well as decrease the expressions of PCK1,glucose-6-phosphatase catalytic(G6PC),and GLUT2 in the liver on d 21(P<0.05)when compared to the free feeding group.These results revealed that Silky chickens have a stronger capability to regulate glucose homeostasis than AA broilers,and feed restriction could improve the fasting blood glucose and the response to oral glucose of AA broilers.

Study of Bacillus subtilis on growth performance, nutrition metabolism and intestinal microflora of 1 to 42 d broiler chickens

To study the influence of different levels of Bacillus subtilis on growth performance, nutrition metabolism and intestinal microflora of 1 to 42 d Arbor Acres(AA) broilers, a total of 800 one-day-old healthy broilers were randomly divided into 5 groups with 4 replicates per group and 40 broilers per replicate. Broilers were fed a basic diet(group 1) which acted as the control group, and 4 other groups(2 to 5) were fed the basal diet with B. subtilis added at concentrations of 100, 150, 200 and 250 mg/kg, respectively for 42 days. The results showed as follow: the average daily gain(ADG) of group 4 was significantly higher than(P < 0.05) that of group 1, and the average daily feed intake(ADFI) of group 5 was the highest but the differences between groups were not significant(P > 0.05). The feed to gain ratio(F/G) of all the experimental groups was lower than that of the control and the difference was significant in group 4(P < 0.05). In addition, supplementation of B. subtilis increased the apparent metabolism of crude protein(P > 0.05), crude fat(P > 0.05), dry matter(P > 0.05) and organic matter(P < 0.05). B. subtilis decreased the Escherichia coli and Salmonella populations in the cecum. This shows that adding B. subtilis to the broiler diet can improve the growth performance, increase feed efficiency, regulate serum index and reduce harmful bacteria in the intestinal tract. Based on our study, it could be recommended that addition of B. subtilis at 200 mg/kg could improve the growth performance of broilers.