Effects Of Lonicera Japonica Extract And Tannic Acid On Productive Performance,Antioxidant Function And Intestinal Morphology Of Layers

The aim of this study was to investigate the effects of dietary supplementation of Lonicera japonica Thunb extract and tannic acid on productive performance and intestinal morphology of laying hens,and 840 healthy15-week-old Jingfan 1 laying hens were randomly divided into three treatments with 10 replicates per treatment and 28 laying hens per replicate using a single-factor experimental design.The three treatment groups were:control group（basal diet）,Lonicera japonica extract group（basal diet+500 mg/kg Lonicera japonica extract）,and tannic acid group（basal diet+250 mg/kg tannic acid）,with a 2-week prefeeding period and a 12-week formal trial.During the experiment,feed intake,egg production and unqualified egg mass were recorded daily in units of each replicate and the number of dead laying hens per day was counted.Blood samples were collected at 20,24 and 28 weeks of age,and 1 chicken from each replicate was slaughtered and sampled before the end of the formal test at 28weeks of age.1.Effects of Lonicera japonica Extract and Tannic Acid on Productive Performance and Egg Quality of Laying HensCompared with the control group,the egg production and laying rate of the Lonicera japonica extract group were significantly increased from the 17th to the20th week of age（P<0.05）.Compared with the control group,the egg yolk color was significantly increased at 20 weeks of age in the Lonicera japonica extract and tannic acid groups（P<0.05）,and the eggshell thickness was significantly decreased in the Lonicera japonica extract group（P<0.05）.Compared with the control group,the Haugh units of eggs at 24 and 28 weeks of age were significantly increased in the Lonicera japonica extract and tannic acid groups（P<0.05）.2.Effects of Lonicera japonica Extract and Tannic Acid on Serum Biochemical Indices and Immunoglobulin Levels in Laying HensCompared with the control group,the plasma total bilirubin（TB）,total protein（TC）and lactate dehydrogenase（LDH）contents of 24-week-old laying hens in the Lonicera japonica extract group were significantly increased（P<0.05）.Compared with the control group,the serum Ig A and Ig G contents of20-week-old laying hens in the Lonicera japonica extract and tannic acid groups were significantly increased（P<0.05）.Compared with the control group,the serum Ig M content of laying hens at 24 and 28 weeks of age was significantly increased in the Lonicera japonica extract and tannic acid groups,and the serum Ig A content was significantly increased in the Lonicera japonica extract group（P<0.05）.3.Effects of Lonicera japonica Extract and Tannic Acid on Organ Index and Follicle Number in Laying HensCompared with the control group,the liver index of 28-week-old laying hens was significantly decreased in the Lonicera japonica extract and tannic acid groups（P<0.05）.Addition of Lonicera japonica extract and tannic acid reduced liver weight in 28-week-old laying hens.Compared with the control group,the number of large follicles（>10 mm）was significantly lower in 28-week-old laying hens in the Lonicera japonica extract and tannic acid groups（P<0.05）.4.Effects of Lonicera japonica Extract and Tannic Acid on Antioxidant Function in Laying HensCompared with the control group,the GSH-Px activity in serum of20-week-old laying hens was significantly increased,the H₂O₂content was significantly decreased,the GSH-Px activity in serum of 24-week-old laying hens was significantly increased,and the CAT activity in serum of 28-week-old laying hens was significantly decreased in the Lonicera japonica extract and tannic acid groups（P<0.05）.Hepatic MDA and H₂O₂contents were significantly decreased,GSH-Px activity in jejunum was significantly increased,and MDA content was significantly decreased（P<0.05）.5.Effect of Lonicera japonica Extract and Tannic Acid on Intestinal Morphology in Laying HensCompared with the control group,Lonicera japonica extract group and tannic acid group significantly increased the intestinal morphological structure of duodenum,jejunum and ileum（P<0.05）.Compared with the control group,the jejunal and ileal villus height and villus height/crypt depth ratio were significantly increased,the jejunal crypt depth was significantly decreased,and the villus area was increased in 28-week-old laying hens in the Lonicera japonica extract and tannic acid groups（P<0.05）.In summary,the addition of Lonicera japonica extract and tannic acid to the diet improved the immunity and antioxidant function as well as intestinal morphology of laying hens and increased the laying rate and egg quality of laying hens during the early stage of laying.