| In order to study the effects of exogenous insulin on feeding,blood glucose metabolites and related gene expression effects in different breeds of chickens,three experiments were designed in this experiment:Experiment 1 Effects of exogenous insulin injection on blood glucose concentration and feeding status of different breed chickensThis study was conducted to explore the effects of insulin injection on blood glucose concentration and feeding status of different breeds chickens.Experiment 1:one hundred and twentymale Hy-line laying hens(abbreviated as laying hens),silky black bone chickens(abbreviated as silky chickens)and Arbor Acres(AA)broilers(abbreviated as broilers)at 21 days of age,respectively,were randomly divided into 4 groups:insulin fasting group(n=60,of which 12 chickens were used to measure dynamic changes of blood glucose concentration,and rest 48 chickens were slaughtered at 15,60,120 and 240 min after insulin injection at each time point,and 10 mL jugular blood was collected to determine serum insulin concentration),phosphate buffered saline(PBS)fasting group(n=12),insulin feeding group(n=24)and PBS feeding group(n=24).All chickens fasted for 16 h before test,injection dose was 5 IU/kg insulin or PBS,chickens in fasting groupswere continued to fasted after injection and used to determine dynamic changes of blood glucose concentration,and chickens in feeding groupswere feeding immediately after injection,one half were used to measure dynamic changes of blood glucose concentration and another half were used to statistics feeding status.Experiment 2:forty eight laying hens,silky chickens and broilers at 44 days of age,respectively,were randomly divided into 2 groups:insulin group(n=24)and PBS group(n=24).All chickens fasted for 16 h before test,injection dose was 2.3 IU/kg insulin or PBS,and the free diet was resumed after 120 minutes of injection,one half in each group were used to measure dynamic changes of blood glucose concentration,and another half were used to statistics feeding statues.The results of the test were as follows:1)insulin injection significantly decreased blood glucose concentration of all breeds chickens at 21 days of age in fasting state(P<0.05).Blood glucose concentration of all breeds chickens was significantly lower than basic blood glucose concentrationafter 15 min of injection and continued to drop until 120 min,blood glucose concentration of broilers were decreased more sharply compared with laying hens and silky chickens,and recovery of blood glucose concentration was significantly lower than that of laying hens and silky chickens after 120 min(P<0.05).Serum insulin concentration of broilers at different time points was higher than that of laying hens and silky chicken after insulin injection;2)Compared with basic blood glucose concentration,feeding immediately significantly decreased blood glucose concentration of laying hens at 21 days of age after insulin injection 60 and 120 min(P<0.05),blood glucose concentration of broilers after insulin injection 30 min and 60 min was significantly increase(P<0.05);3)Feed immediately after insulin injection had no significant effect on cumulative feed intake of all breeds chickens in 240 min,significantly decreased feed intake laying hens and silky chickens at 21 days of age after insulin injection from 120 to 240 min(P<0.05),significantly increase feed intake of broilers after insulin injection from 30 to 60 min(P<0.05);4)Feeding after insulin injection 120 min significantly decreased food intake of all breeds chickens at 44 days of age(P<0.05).Experiment 2 Effects of exogenous insulin injection on serum biochemical indexes and tissue metabolites ofdifferent breed chickensThe purpose of this test was to investigate the effects of exogenous insulin on serum biochemical parameters and tissue metabolites in different breeds of chickens.The test chickens included laying hens,silky chickens,and broilers,all of which were roosters.They were free to eat and drink,and fasted for 16 hours before the test.Choose the age of 24,laying hens,silky chickens and and broilers,90 were randomly divided into two groups:insulin group and PBS group(control group).The injection dose was 5 IU/kg insulin or the same dose of PBS solution.after the injection of 0,15,120,240(half has been in the fasting state,half 120 min after injection recovery feeding)min slaughter sampling,each group slaughtered 10 chickens at each time point.The test results are as follows:1)The effects of breed and time of insulin on the content of glucose.insulin.urea,uric acid,total cholesterol and triglyceride in serum were significant(P<0.05).and the interaction effect of breed and time on content of glucose,urea.uric acid and triglyceride content in serum were significant(P<0.05):2)Compared with the control group,the insulin group significantly reduced glucose and urea levels in serum of chickens of various breeds(P<0.05)compared with the control group after insulin injection 120 min,and significantly increased the levels of uric acid,globulin,Triglyceride,total cholesterol,low-density lipoprotein,and albumin levels(P<0.05);240 minutes after insulin injection,the glucose and urea levels in the insulin group were significantly lower than those in the control group,and the uric acid levels were significantly higher in the control group(P<0.05);3)The exogenous insulin injections for 15 min and 120 min after each type chickens were significantly decreased the glucose and glycogen content of liver tissue compared with basic status(0 min)(P<0.05),but increased insulin levels in liver tissue,and liver tissue insulin in the glucose content of 120 min group was significantly lower than the control group(P<0.05);4)Exogenous insulin injection significantly increased the glucose content in the breast muscle tissue of silky chicken and broiler chickens(P<0.05),reduced the glycogen and insulin content,and the glucose content of the insulin and broiler chickens for 120 min was significantly higher than that Control group(P<0.05);5)After 120 min of exogenous insulin injection,the glucose content in the muscle tissues of laying hens and broilers significantly increased(P<0.05),and the glucose content in the insulin 120 min group of laying hens and broilers was significantly higher than that in the control group(P<0.05).Experiment 3 Effect of exogenous insulin injection on glucose metabolism gene expression of different breed chickensThe purpose of this experiment was to investigate the effect of exogenous insulin injection on the expression effects of blood glucose metabolism genes in different breeds of chickens.The test chickens included laying hens,silky chickens,and broilers,all of which were roosters.They were free to eat and drink,and fasted for 16 hours before the test.Choose the age of 24,laying hens,silky chickens and and broilers,90 were randomly divided into two groups:insulin group and PBS group(control group).The chickens were kept on a fast throughout the experiment.The injection dose was 5 IU/kg insulin or the same dose of PBS solution.after the injection of 0.15,120,240 min slaughter sampling,each group slaughtered 10 chickens at each time point.The test results are as follows:1)In the basal state.the expression levels of IR.GLUT3 in duodenum,GLUT5 in liver,pectoral muscle-abdominal fat and duodenum,GLUT8 in liver,pectoral muscle and duodenum,and GLUT9 in liver,pectoral muscle and duodenum were significantly higher in laying hens than in silky chicken and broiler chickens(P<0.05);2)Compared with the basal state of 0 min,insulin injection significantly increased the expression of GLUT3 in the pectoral muscle and duodenum of the chicken at 24 d for 15 min and 240 min(P<0.05),and significantly increased the expression of GLUT3 in the pectoral muscle and duodenum of the chicken at 24 d for 240 min(P<0.05).GLUT3 expression in the pectorals and duodenum of broilers was also significantly increased when insulin was injected externally for 240 min,compared with the control group(P<0.05);3)Insulin injection significantly increased the expression levels of GLUT8 and GLUT9 in liver tissues of silky chicken and broiler chicken(P<0.05),but there was no significant difference in layers(P>0.05).Compared with the control group,GLUT8 expression levels in liver,pectorals,abdominal fat and duodenum tissues of silky chicken were significantly reduced after exogenous insulin injection for 120 min(P<0.05).The expression levels of GLUT9 in the liver,pectorals muscle and duodenum of laying hens were significantly increased(P<0.05);4)Insulin injection significantly reduced the expression of GLUT5 in the duodenal tissues of laying hens and black pheasants.There was a downward trend in broilers but the difference was not significant(P>0.05).When insulin was injected at 120 min,compared with the control group,the expression of GLUT5 in the duodenum of laying hens was significantly increased(P<0.05),and it was significantly reduced in the liver tissues of broilers(P<0.05),but there was no significant difference in silky chickens(P<0.05);5)There were significant differences between breeds and insulin action time on glucose metabolism genes in different breeds of chickens,and the response of glucose metabolism genes in different breeds to exogenous insulin was different in each tissue;6)when exogenous insulin was injected for 120 min,the expression levels of GLUT12,GLUT2 and IR in the liver tissues of the laying hens and silky chickens insulin groups were significantly reduced compared with the control group(P<0.05).In other words,when exogenous insulin was injected for 120 min,the compensation mechanism for further hypoglycemia in the liver tissues was generated in the laying hens and silky chickens.In summary,the effects of insulin injection on dietary intake,blood glucose metabolites and related gene expression of different chicken breeds were studied.and it was found that the blood glucose regulation ability of laying hens and silky chickens were better than that of broilers,and the blood glucose metabolism rules of different breeds were different,which provided a theoretical basis for further research on the blood glucose regulation mechanism of poultry. |
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