Dietary Naringin Supplementation On Laying Performance Of Guang Xi Three-yellow Breeder Hens During The Late Laying Period

During the late laying period,egg production of the hen declines sharply.Previous studies showed that dietary supplementation with plant-derived antioxidants could improve laying performance in hens during the late laying period.In this experiment,naringin was added to the diet to explore its effects on the laying performance of Guangxi Three-Yellow breeder hens during the late laying period.A total of 480 healthy Guangxi Three-Yellow breeder hens（54 weeks）in the same status of health and laying rate were randomly allocated into 4 groups,each group with 6 replicates（20 hens/replicate）:control group was fed with basal diet（C）,treatment groups received a basal diet supplemented with 0.1%,0.2%,and 0.4%of naringin（N1,N2,and N3）,respectively.The experiment lasted for 8 weeks,and the experimental results were as follows:（1）Effect of naringin on laying performance and serum antioxidant capacityStarting from the 4 weeks of the experiment,the laying rate of hens in three treatment groups was remarkably increased（P<0.05）.Starting from the7 weeks of the experiment,the laying rate of N2 and N3 groups was significantly higher than that of N1 group.After 4 and 8 weeks of feeding,the egg production increased significantly and the feed egg ratio decreased significantly.After 8 weeks of feeding,the yolk color and the activities of antioxidant enzymes in the serum significantly increased,and the concentrations of oxidized products were decreased significantly in the treatment groups（P<0.05）.The results showed that dietary naringini supplementation improved the laying rate and egg production,reduced the feed egg ratio,and enhanced the antioxidant capacity in the serum of Guang Xi Three-Yellow breeder hens during the late laying period.（2）Effect of naringin on ovary morphology,function and antioxidant capacityAfter 8 weeks of feeding,more growing follicles were observed in ovary of treatment groups,and the number of preovulatory follicles increased.Ovarian index and the expression levels of proteins related to cell proliferation in ovarian tissues of treatment groups significant increased（P<0.05）.The activities of antioxidant enzymes in ovary were significantly increased,the concentrations of oxidized products were significantly reduced,and the transcription levels of genes related to antioxidation-related was significantly increased.The results showed that dietary supplemented with naringin could improve ovarian function and enhance ovarian antioxidant capacity.（3）Effect of naringin on hepatic yolk precursors formation and antioxidant capacityAfter 8 weeks of feeding,the liver lipid accumulation decreased,the expression levels of proteins related to cell proliferation increased in liver tissues,and the function of yolk precursor formation increased（P<0.05）.Serum estrogen（E₂）level and hepatic estrogen receptors（ERs）expression increased significantly in treatment groups（P<0.05）.The transcription levels of genes related to the yolk precursors synthesis and transportation were significantly increased,the activity of antioxidant enzymes was significantly increased,the concentration of oxidized products was significantly decreased,and the transcription levels of genes related to antioxidation in liver were significantly increased（P<0.05）.These results indicate that dietary supplemented with naringin promotes the formation of yolk precursors and enhance the antioxidant capacity of liver.In conclusion,dietary naringin supplementation could improve the laying performance of Guangxi Three-Yellow breeder hens during the late laying period via increasing the number of ovarian follicles,elevating serum estrogen level,improving yolk precursor formation,enhancing the antioxidant capacity of liver and ovary.Taken together,the 0.2%and 0.4%naringin treatment are more helpful than 0.1%.