Effects Of L-theanine On Productive Performance And Egg Quality Of Ling Nanhuang Breeding Broilers In Late Laying Period

In the intensive breeding mode,broiler breeders is filling stress long-term because of high density,small activity space and so on.This makes the broiler breeder are easily suffered from environmental factors and produce a variety of problems.L-theanine is a kind of functional additive which can reduce blood pressure,enhance immunity,promote lipid metabolism,anti-tumor,anti fatigue,anti stress,anti-oxidation,sedation and relaxation.The aim of this study was to compare the productive performance,breeding function,antioxidant capacity,immune function,serum biochemistry and egg quality of Ling Nanhuang broiler breeders in late laying period by fed diets containing L-theanine.A total of 1296,52-week-old Ling Nanhuang broiler breeders were purchased from a commercial hatchery and randomly assigned into 6groups with 6 replicates in each group and 36 hens in each replicate The control group and test groups were fed with diets supplemented with L-theanine at 0mg/Kg,100mg/Kg,200mg/Kg and 400mg/Kg,800mg/Kg and 1 600mg/Kg in the middle of ladder cage,respectively.The whole experiment lasted for 8 weeks.After the experiment,2 hens respectively from each replicate were killed by a lethal dose of sodium pentobarbital injected intraperitoneally after a 12 hours fast for slaughter.The samples were collected for laboratory analysis and determination according to the methods of determination by each index.The main results are as following:1.Effects of different levels of L-theanine on performance.Compared with the control group,the laying rate had no significant difference among each group(P>0.05),but total defective egg rate,sand shell egg rate and malformed egg rate had all significant decreased in group 100 pm,200mg/Kg and 1 600mg/Kg(P<0.01);The average egg weight had significantly decreased in group 100mg/Kg,400mg/Kg,800mg/Kg and 1600mg/Kg(P<0.01),and group 200mg/Kg had achieved significant difference level(P<0.05).Compared with the control,all groups had no significant influence in live embryo rate,fertilization rate,healthy chick rate,hatching rate of living embryo and total hatching rate(P>0.05).The serum LH and FSH level had increased first and then decreased with the increase of dose in all test groups,while L-theanine group 200mg/Kg had significantly increased the serum LH and FSH level(P<0.05)and group 1 600mg/Kg had significant decreased in serum FSH level.The relative expression of FSHR mRNA and LHR m RNA had also increased first and then decreased with the increase of dose,while L-theanine group 200mg/Kg had significantly increased the relative expression of FSHR mRNA and LHR mRNA(P<0.05),but group1600mg/Kg had significantly decreased the relative expression of FSHR m RNA.2.Effects of different levels of L-theanine on immune performance.Compared with the control,L-theanine group 400mg/Kg and 800mg/Kg had significantly increased the serum IgM level(P<0.05),200mg/Kg,400mg/Kg and 800mg/Kg had significantly increased the serum IgA level(P<0.01),group200mg/Kg and 400mg/Kg had significantly increased the serum IgG level(P<0.05).Compared with the control,the serum IFN-? level had increased in different level in all groups,the difference of L-theanine400mg/Kg were significant(P<0.05)and 1 600mg/Kg were extremely significant(P<0.01).Besides,wefound that all groups had no influence on serum IL-2,IL-4 and thymus index,spleen index(P>0.05).3.Effects of different levels of L-theanine on antioxidant capacity in serum.Compared with the control,all test groups had increased the serum T-AOC,T-SOD and GSH-Px activity,group 200mg/Kg had significantly increased the serum T-AOC activity(P<0.01),group 400mg/Kg had significantly increased the serum T-AOC activity(P<0.05),group 1 600mg/Kg had significantly increased the serum T-SOD activity(P<0.01),group 200mg/Kg had significantly increased the serum GSH-Px activity(P<0.05).Mean while,all test groups had decreased the serum MDA level in different degree,group 200mg/Kg and 400mg/Kg both achieved significant difference level(P<0.05).L-theanine group 200mg/Kg had significantly increased the liver T-SOD activity(P<0.05),and the liver MDA level had significantly decreased in all test groups(P<0.01).4.Effects of different levels of L-theanine on biochemistry in serum.Compared with the control,all test groups had increased the serum TP and Glob level,but no significant difference was found in each group(P>0.05);L-theanine group 200mg/Kg had significantly increased the serum ALB level(P<0.05);All test group had decreased the serum AST,ALT activity and Ca,P,Urea content in different level,group200mg/Kg and 800mg/Kg both significantly decreased the serum ALT content(P<0.05),group 400mg/Kg had significantly decreased the serum ALT content(P<0.01),group 1 600mg/Kg had significantly decreased the serum Ca content(P<0.05),group 800mg/Kg and 1 600mg/Kg both significantly decreased the serum P content(P<0.05),group 100mg/Kg,200mg/Kg,400mg/Kg and 800mg/Kg all significantly decreased the serum Urea content(P<0.01)and group 1 600mg/Kg had significantly decreased the serum Urea content(P<0.05).L-theanine group 200mg/Kg,400mg/Kg and 1 600mg/Kg had significantly increased the serum ALP activity(P<0.05),group 800mg/Kg had significantly increased the serum ALP activity(P<0.01).5.Effects of different levels of L-theanine on egg quality.Compared with the control,all test groups had no significant influence on albumen height,yolk color,haugh unit,eggshell thickness and eggshell strength.(P>0.05).Based on the results showed above,the result suggest that adding suitable L-theanine in the diet of Ling Nanhunag broiler breeders in late laying period can significantly decrease the defective egg rate,promote the release of immune factors,adjust the balance of amino acid,prevent fatty acid oxidation,promote the secretion of gonadotropin and raise the relative expression of corresponding genes.No negative effect was found on laying performance,hatching performance and egg quality.This study provides a reliable evidence for the wide use of L-theanine in animal husbandry.