| This experiment was conducted to investigate the effects of glucose oxidase with different supplemental levels on the performance,egg quality,apparent metabolic rate of nutrients,reproductive performance and antioxidant capacity of Hy-Line brown laying breeders in the late laying stage.The appropriate amount of glucose oxidase added to the diet was determined by comparing the effects of different doses of glucose oxidase on the actual production of Hy-Line brown laying breeders in the late laying stage.Through our research,a nutritional strategy of improving the production performance,reproductive performance and antioxidant capacity of Hy-Line brown laying breeders will be obtained,which can provide scientific basis for the research and application of high-efficiency breeding technology of Hy-Line brown laying breeders.480 healthy 55-week-old Hy-Line brown laying breeders with the same egg production rate and body weight were selected in the laying hen house.They were randomly assigned to 4 groups with 6 replicates in each group and each replicate contained 20 chickens.The control group was fed with corn-soybean meal basic diet.The experimental group was fed with 200,350 and 500 mg/kg of glucose oxidase in the basic diet,respectively.The pre-trial period is 1 week and the trial period is 12 weeks.The results are as follows:(1)Glucose oxidase has different degrees of influence on the performance of Hy-Line brown laying breeders in the late laying stage.compared with the control group,the feed conversion ratio were decreased In all stages of the experiment,while those of 350 mg/kg and 500 mg/kg glucose oxidase groups were decreased significantly(P<0.05),but there was no significant difference between the two groups(P>0.05).compared with the control group,The laying rate were increased,while those of 350 mg/kg and 500 mg/kg glucose oxidase groups were significantly higher than those of the control group(P<0.05),but there was no significant difference between the two groups(P>0.05).The feed conversion ratio of the three groups were decreased by 2.47%,10.95% and 10.60% in 1-6 weeks,2.81%,11.58% and 10.88% in 7-12 weeks,2.60%,11.10% and 10.56% in 1-12 weeks,respectively.compared with the control group,The laying rate were increased.while those of 350 mg/kg and 500 mg/kg glucose oxidase groups were significantly increased than those of the control group(P<0.05),but there was no significant difference between the two groups(P>0.05).The laying rate of the three groups were increased by 3.30%,9.19% and 8.53% in 1-6 weeks,2.40%,7.61% and 7.93% in 7-12 weeks,The average daily feed intake and average egg weight of Hy-Line brown laying breeders at the late laying stage were not significantly affected by different levels of glucose oxidase(P>0.05).(2)Glucose oxidase has different degrees of influence on shell thickness and Harrington unit of Hy-Line brown laying breeders in the late laying stage.Compared with the control group,the eggshell thickness of 200 mg/kg,350 mg/kg and 500 mg/kg glucose oxidase groups were increased by 2.86%(P>0.05),5.71%(P<0.05)and 6.28%(P<0.05)at the end of the 6th week,2.85%(P>0.05),5.41%(P<0.05)and 5.70%(P<0.05)at the end of the 12 th weekend,respectively,the Harrington unit of 200 mg/kg,350 mg/kg and 500 mg/kg glucose oxidase groups were increased by 2.09%(P>0.05),9.73%(P<0.05)and 10.49%(P<0.05)on the sixth weekend,2.42%(P>0.05),6.30%(P<0.05)and 7.15%(P<0.05)at the end of the 12 th week,There was no significant influence of different levels of glucose oxidase on shell strength,protein height and egg shape index of Hy-Line brown laying breeders at the later stage of laying(P>0.05).(3)Glucose oxidase has different degrees of influence on crude protein and phosphorus apparent metabolic rate of Hy-Line brown laying breeders in the late laying stage.Compared with the control group,the apparent metabolic rates of crude protein in 200,350 and 500 mg/kg glucose oxidase groups were increased by 7.84%(P>0.05),22.47%(P<0.05)and 23.81%(P<0.05),respectively.The apparent metabolic rates of phosphorus were increased by 6.82%(P>0.05),26.18%(P<0.05),29.47%(P<0.05),and there was no significant difference between 350 mg/kg and 500 mg/kg glucose oxidase groups(P>0.05).The level of glucose oxidase has no significant influence on the apparent metabolic rate of calcium and energy in Hy-Line brown laying breeders at the late laying stage(P>0.05).(4)Glucose oxidase has different degrees of influence on the fertilization rate of Hy-Line brown laying breeders in the late laying stage.Compared with the control group,the fertilization rates of 200,350 and 500 mg/kg glucose oxidase groups were increased by 14.42%(P<0.05),12.68%(P<0.05)and 18.86%(P<0.05)at the end of the 6th week,18.71%(P<0.05),19.30%(P<0.05)and 25.43%(P<0.05)at the end of the 12 th week,respectively.Glucose oxidase at different levels has no significant influence on the dead embryo rate,fertilized egg laying rate,hatching rate and healthy chick rate of Hy-Line brown laying breeders at the late laying stage(P>0.05).(5)Glucose oxidase has different degrees of influence on the number of large white follicles of Hy-Line brown laying breeders in the late laying stage.Compared with the control group,the number of large white follicles in 200,350 and 500 mg/kg glucose oxidase groups were increased by 8.73%(P>0.05),28.73%(P<0.05)and 35.05%(P<0.05),respectively,and there was no significant difference between 350 mg/kg and 500 mg/kg glucose oxidase groups(P>0.05).The number of pre-ovulation follicles and small yolk follicles in Hy-Line brown laying breeders with different levels of added glucose oxidase was not significant difference(P>0.05).(6)The serum estradiol,follicle stimulating hormone and progesterone levels of Hy-Line brown laying breeders were increased in different degrees with the increase of the dietary glucose oxidase levels.Among them,350 mg/kg and 500 mg/kg glucose oxidase groups were significantly increased than those of the control group(P<0.05),but there was no significant difference between the two groups(P>0.05).(7)With the increase of the level of glucose oxidase in diet,the activities of SOD and T-AOC in serum of Hy-Line brown laying breeders in the late laying stage were significantly increased than those of the control group(P<0.05),and there was no significant difference among the three experimental groups(P>0.05),while the activities of GSH-Px in serum of 350 mg/kg and 500 mg/kg glucose oxidase groups were significantly increased(P<0.05),but there was no significant difference between the two groups(P>0.05).The activity of MDA in serum of 500 mg/kg glucose oxidase group was significantly decreased than that of control group(P<0.05).The activities of SOD and GSH-Px in liver of Hy-Line brown laying breeders were significantly increased with the increase of the level of glucose oxidase in diet.The 350 mg/kg and 500 mg/kg groups were better(P<0.05),and there was no significant difference between the two groups(P>0.05);the activities of MDA in liver was significantly decreased,and there was no significant difference among the experimental groups(P > 0.05).In conclusion,the optimum amount of glucose oxidase in the diet of laying hens was 350 mg/kg under the experimental conditions in the late laying stage. |
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