Prevotella and succinate treatments altered gut microbiota,increased laying performance,and suppressed hepatic lipid accumulation in laying hens

Background This work aimed to investigate the potential benefits of administering Prevotella and its primary metabolite succinate on performance,hepatic lipid accumulation and gut microbiota in laying hens.Results One hundred and fifty 58-week-old Hyline Brown laying hens,with laying rate below 80%and plasma triglyceride(TG)exceeding 5 mmol/L,were used in this study.The hens were randomly allocated into 5 groups and subjected to one of the following treatments:fed with a basal diet(negative control,NC),oral gavage of 3 mL/hen saline every other day(positive control,PC),gavage of 3 mL/hen Prevotella melaninogenica(10^(7)CFU/mL,PM)or 3 mL/hen Prevotella copri(10^(7)CFU/mL,P.copri)every other day,and basal diet supplemented with 0.25%sodium succinate(Succinate).The results showed that PM and P.copri treatments significantly improved laying rate compared to the PC(P<0.05).The amount of lipid droplet was notably decreased by PM,P.copri,and Succinate treatments at week 4 and decreased by P.copri at week 8(P<0.05).Correspondingly,the plasma TG level in Succinate group was lower than that of PC(P<0.05).Hepatic TG content,however,was not significantly influenced at week 4 and 8(P>0.05).PM treatment increased(P<0.05)the mRNA levels of genes PGC-1βand APB-5B at week 4,and ACC and CPT-1 at week 8.The results indicated enhanced antioxidant activities at week 8,as evidenced by reduced hepatic malondialdehyde(MDA)level and improved antioxidant enzymes activities in PM and Succinate groups(P<0.05).Supplementing with Prevotella or succinate can alter the cecal microbiota.Specifically,the abundance of Prevotella in the Succinate group was significantly higher than that in the other 4 groups at the family and genus levels(P<0.05).Conclusions Oral intake of Prevotella and dietary supplementation of succinate can ameliorate lipid metabolism of laying hens.The beneficial effect of Prevotella is consistent across different species.The finding highlights that succinate,the primary metabolite of Prevotella,represents a more feasible feed additive for alleviating fatty liver in laying hens.

基于蓝墨云教学平台的实验(训)课设计方案研究——以高职《汽车构造》课程为例

针对职业教育传统实验(训)课堂教学效果不佳的问题,在智慧校园中,结合蓝墨云班课教学经验,以高职《汽车构造》课程为例,采用相关分析法和对应分析法阐述了基于蓝墨云教学平台的“一纵两横”实验(训)课设计方案,并对其应用效果进行了分析。以时间轴为线索,课前、课中、课后纵向引领;以班课资源和班课活动为依托,实现实训空间的横向延展和知识技能的横向拓展。“一纵两横”设计方案在两个实验班级中应用,使课堂集智能、高效于一体,实现课堂翻转,彰显了学生学习的自主性,有效提升了教学质量。

中国西南地区藏族人群遗传亚结构研究

藏族为中国西南地区典型的少数民族,分为卫藏、康巴、安多和嘉绒等多个支系。然而,对藏族支系人群的遗传结构,特别是各分支人群的父系、母系遗传结构却缺乏深度解析。本研究基于个体水平的常染色体、父系来源的Y染色体和母系来源的线粒体3个类别遗传信息,对西藏地区卫藏藏族、四川甘孜地区康巴藏族、青海地区安多藏族和四川阿坝地区嘉绒藏族共4个藏族群体进行研究,以揭示其遗传亚结构关系。采用微测序技术检测各位点分型,利用PowerPlex^■Y23和DNATyper^TM Y26试剂盒检测Y-STRs基因座分型,通过热图和主成分分析、祖先成分分析、单倍群频率统计、网络图及多维尺度分析等探讨其遗传亚结构。结果表明,常染色体和Y染色体遗传标记可将4个藏族人群分为3类:青藏高原的卫藏藏族为一类,高原周边地区的康巴藏族和安多藏族的遗传结构类似分为一类,“藏彝走廊”中嘉绒藏族的遗传结构与其他藏族人群差异显著而为一类。不同藏族分支人群在线粒体遗传信息方面无明显差异性。上述多类别遗传信息的分析结果为深入了解藏族不同分支人群的遗传亚结构提供了新视角。

Adaptive subsequence adjustment with evolutionary asymmetric path-relinking for TDRSS scheduling

Due to the limited transmission resources for data relay in the tracking and data relay satellite system （TDRSS）, there are many job requirements in busy days which will be discarded in the conventional job scheduling model. Therefore, the improvement of scheduling efficiency in the TDRSS can not only help to increase the resource utilities, but also to reduce the scheduling failure ratio. A model of nonhomogeneous parallel machines scheduling problems with time window （NPM-TW） is firstly built up for the TDRSS, considering the distinct features of the variable preparation time and the nonhomogeneous transmission rates for different types of antennas on each tracking and data relay satellite （TDRS）. Then, an adaptive subsequence adjustment （ASA） framework with evolutionary asymmetric path-relinking （EvAPR） is proposed to solve this problem, in which an asymmetric progressive crossover operation is involved to overcome the local optima by the conventional job inserting methods. The numerical results show that, compared with the classical greedy randomized adaptive search procedure （GRASP） algorithm, the scheduling failure ratio of jobs can be reduced over 11% on average by the proposed ASA with EvAPR.

Rabdosia serra alleviates dextran sulfate sodium salt-induced colitis in mice through anti-inflammation,regulating Th17/Treg balance,maintaining intestinal barrier integrity,and modulating gut microbiota

Rabdosia serra(R.serra),an important component of Chinese herbal tea,has traditionally been used to treat hepatitis,jaundice,cholecystitis,and colitis.However,the chemical composition of R.serra and its effect against colitis remain unclear.In this study,the chemical composition of the water extract of R.serra was analyzed using ultra performance liquid chromatography coupled with a hybrid linear ion trap quadrupole-orbitrap mass spectrometer(UPLC-LTQ-Orbitrap-MS).A total of 46 compounds,comprising ent-kaurane diterpenoids,flavonoids,phenolic acids,and steroids,were identified in the water extract of R.serra,and the extract could significantly alleviate dextran sulfate sodium salt-induced colitis by improving colon length,upregulating anti-inflammatory factors,downregulating proinflammatory factors,and restoring the balance of T helper 17/T regulatory cells.R.serra also preserved intestinal barrier function by increasing the level of tight junction proteins(zonula occludens 1 and occludin)in mouse colonic tissue.In addition,R.serra modulated the gut microbiota composition by increasing bacterial richness and diversity,increasing the abundance of beneficial bacteria(Muribaculaceae,Bacteroides,Lactobacillus,and Prevotellaceae_UCG-001),and decreasing the abundance of pathogenic bacteria(Turicibacter,Eubacterium_fissicatena_group,and Eubacterium_xylanophilum_group).Gut microbiota depletion by antibiotics further confirmed that R.serra alleviated colitis in a microbiota-dependent manner.Overall,our findings provide chemical and biological evidence for the potential application of R.serra in the management of colitis.

The fate of fertilizer N applied to cotton in relation to irrigation methods and N dosage in arid area

Quantitative information on the fate and efficiency of nitrogen （N） fertilizer applied to coarse textured calcareous soils in arid farming systems is scarce but, as systems intensify, is essential to support sustainable ag- ronomic management decisions. A mesh house study was undertaken to trace the fate of N fertilizer applied to cotton （Gossypium hirsutum L. cv., Huiyuan701） growing on a reconstructed profile （0-100 cm） of a calcareous （〉15% CaCQ） sandy loam soil. Two irrigation methods （drip irrigation, DI; and furrow irrigation, FI） and four N ap- plication rates （0, 240, 360 and 480 kg/hm2, abbreviated as No, N240, N360, and N480, respectively） were applied. 15N-labelled urea fertilizer was applied in a split application. DI enhanced the biomass of whole plant and all parts of the plant, except for root; more fertilizer N was taken up and mostly stored in vegetative parts; N utilization efficiency （NUE） was significantly greater than in FI. N utilization efficiency （NUE） decreased from 52.59% in N240 to 36.44% in N480. N residue in soil and plant N uptake increased with increased N dosage, but recovery rate decreased consis- tently both in DI and Fl. Plant N uptake and soil N residue were greater in DI than in FI. N residue mainly stayed within 0-40 cm depth in DI but within 40-80 cm depth in Ft. FI showed 17.89% of N leached out, but no N leaching occurred in DI. N recovery rate in the soil-plant system was 75.82% in DI, which was markedly greater than the 55.97% in FI. DI exhibited greater NUE, greater residual N in the soil profile and therefore greater N recovery rate than in FI; also, N distribution in soil profile shallowed in DI, resulting in a reduced risk of N leaching compared to FI; and enhanced shoot growth and reduced root growth in DI is beneficial for more economic yield formation. Com- pared to furrow irrigation, drip irrigation is an irrigation method where N movement favors the prevention of N from being lost in the plant-soil system and benefits a more efficient use of N.

Functional roles of taurine,L-theanine,Lcitrulline,and betaine during heat stress in poultry

Heat stress(HS)is an important environmental stress factor affecting poultry production on a global scale.With the rise in ambient temperature and increasing effects of global warming,it becomes pertinent to understand the effects of HS on poultry production and the strategies that can be adopted to mitigate its detrimental impacts on the performance,health,welfare,immunity,and survival of birds.Amino acids(AAs)have been increasingly adopted as nutritional modifiers in animals to ameliorate the adverse effects of HS.They are essential for protein synthesis,growth,maintenance,reproduction,immunity,stress response,and whole-body homeostasis.However,HS tends to adversely affect the availability,transport,absorption,and utilization of these AAs.Studies have investigated the provision of these AAs to poultry during HS conditions,and variable findings have been reported.Taurine,L-theanine,and L-citrulline are non-essential amino acids that are increasingly gaining attention as nutritional supplements in HS animals.Similarly,betaine is an amino acid derivative that possesses favorable biological properties which contributes to its role as a functional additive during HS.Of particular note,taurine is negligible in plants,while betaine,L-theanine,and L-citrulline can be found in selected plants.These nutrients are barely found in feed ingredients,but their supply has been shown to elicit important physiological roles including anti-stress effects,anti-oxidative,anti-inflammatory,gut promoting,and immunomodulatory functions.The present review provides information on the use of these nutritionally and physiologically beneficial nutrients as functional additives to poultry diets during HS conditions.Presently,although several studies have reported on the positive effects of these additives in human and murine studies,however,there is limited information regarding their utilization during heat stress in poultry nutrition.Therefore,this review aims to expound on the functional properties of these nutrients,their potentials for HS alleviation,and to stimulate further researches on their biological roles in poultry nutrition.

Cell viability and dopamine secretion of 6-hydroxydopamine-treated PC12 cells co-cultured with bone marrow-derived mesenchymal stem cells

In the present study, PC12 cells induced by 6-hydroxydopamine as a model of Parkinson＇s Disease, were used to investigate the protective effects of bone marrow-derived mesenchymal stem cells bone marrow-derived mesenchymal stem cells against 6-hydroxydopamine-induced neurotoxicity and to verify whether the mechanism of action relates to abnormal a-synuclein accumulation in cells Results showed that co-culture with bone marrow-derived mesenchymal stem cells enhanced PC12 cell viability and dopamine secretion in a cell dose-dependent manner. MitoLight staining was used to confirm that PC12 cells co-cultured with bone marrow-derived mesenchymal stem cells demonstrate reduced levels of cell apoptosis. Immunocytochemistry and western blot analysis found the quantity of α-synuclein accumulation was significantly reduced in PC12 cell and bone marrow-derived mesenchymal stem cell co-cultures. These results indicate that bone marrow-derived mesenchymal stem cells can attenuate 6-hydroxydopamine-induced cytotoxicity by reducing abnormal α-synuclein accumulation in PC12 cells.

Drug-drug cocrystals:Opportunities and challenges

Recently,drug-drug cocrystal attracts more and more attention.It offers a low risk,low-cost but high reward route to new and better medicines and could improve the physiochemical and biopharmaceutical properties of a medicine by addition of a suitable therapeutically effective component without any chemical modification.Having so many advantages,to date,the reported drug-drug cocrystals are rare.Here we review the drug-drug cocrystals that reported in last decade and shed light on the opportunities and challenges for the development of drug-drug cocrystals.

The optimal dietary arginine level of laying hens fed with low-protein diets

Background:Arginine(Arg)is an essential amino acid(EAA)in poultry,an important substrate for protein synthesis and a precursor of several molecules.Supplementation of EAAs with low protein(LP)diet increases the utilization efficiency of dietary crude protein(CP).However,if the EAA requirement is changed in hens fed a LP diet remains to be elucidated.The aim of the present study was to evaluate the optimal level of dietary Arg in the LP diet of hens.A total of 1350 Hy-Line Brown laying hens were randomly allocated to six dietary treatments:a basal diet(16%CP,positive control),or an isoenergetic LP diet(14%CP,0.80%Arg)supplemented 0,0.05%,0.10%,0.15%,and 0.20%L-Arg,corresponding to 0.80%,0.85%,0.90%,0.95%and 1.00%dietary Arg,respectively.Results:The feed efficiency was decreased(P<0.05)by 0.80%and 1.00%Arg-LP diets,compared to control.Within LP diets,dietary Arg level had significant quadratic effects(P<0.05)on laying rate,egg mass,and feed efficiency.Compared to control,the plasma CAT activity or T-AOC content were decreased by 0.80%(P<0.001).However,the hens offered 0.85%and 0.90%Arg-LP diets had higher CAT activity(P<0.001)than 0.80%Arg-LP diet.In contrast,1.00%Arg-LP group had the highest MDA and the lowest T-AOC content in plasma,liver,duodenal and jejunal mucosa(P<0.05).Compared to control,the villus height was decreased by 0.80%,0.95%and 1.00%Arg-LP diets,while the villus height to crypt depth(V/C)ratio was reduced by 0.95%and 1.00%Arg-LP diets in duodenum.Conclusion:The result demonstrates that LP diet(14%CP)deficient in Arg(0.80%Arg)result in augmented oxidative damage and impaired development of intestinal mucosa.According to the quadratic broken-line regression model,the optimal dietary arginine levels for Hy-Line Brown laying hens fed with low protein diet(14%CP)aged 33 to 40 weeks are 0.85%,0.86%,and 0.86%to obtained the maximum laying rate,egg mass,and feed efficiency,respectively.

Stability of mixed-halide wide bandgap perovskite solar cells: Strategies and progress

Benefiting from the superior optoelectronic properties and low-cost manufacturing techniques,mixedhalide wide bandgap(WBG)perovskite solar cells(PSCs)are currently considered as ideal top cells for fabricating multi-junction or tandem solar cells,which are designed to beyond the Shockley-Queisser(S-Q)limit of single-junction solar cells.However,the poor long-term operational stability of WBG PSCs limits their further employment and hinders the marketization of multi-junction or tandem solar cells.In this review,recent progresses on improving environmental stability of mixed-halide WBG PSCs through different strategies,including compositional engineering,additive engineering,interface engineering,and other strategies,are summarized.Then,the outlook and potential direction are discussed and explored to promote the further development of WBG PSCs and their applications in multijunction or tandem solar cells.

Application of sodium alginate microspheres in ischemic stroke modeling in miniature pigs

The miniature pig is an optimal animal model for studying nervous system disease because of its physiologic and pathologic features. However, the rete mirabile composed of arteries and veins at the skull base limits their application as a model of ischemic stroke by middle cerebral artery occlusion. The present study investigated the possibility of establishing an ischemic stroke model in the miniature pig by blocking the skull base retia with sodium alginate microspheres. Three Bama miniature pigs were used. Using the monitor of C-arm X-ray machine, sodium aiginate microspheres （100-300 pm）, a novel embolic material, were injected through the femoral artery, aortic arch, common carotid artery, ascending pharyngeal artery and the retia. Results were evaluated using carotid arteriography, MRI, behavior observation and histology. The unilateral rete mirabile was completely blocked, resulting in disturbance in blood supply to the basal ganglia, astasia of the dght hind limb and salivation. MRI and hematoxylin-eosin staining showed an evident infarction focus in the basal ganglia. These findings indicate that sodium alginate microspheres are a suitable embolic material for blocking the skull base retia in miniature pigs to establish an ischemic stroke models.

A Network Traffic Classification Model Based on Metric Learning

Attacks on websites and network servers are among the most critical threats in network security.Network behavior identification is one of the most effective ways to identify malicious network intrusions.Analyzing abnormal network traffic patterns and traffic classification based on labeled network traffic data are among the most effective approaches for network behavior identification.Traditional methods for network traffic classification utilize algorithms such as Naive Bayes,Decision Tree and XGBoost.However,network traffic classification,which is required for network behavior identification,generally suffers from the problem of low accuracy even with the recently proposed deep learning models.To improve network traffic classification accuracy thus improving network intrusion detection rate,this paper proposes a new network traffic classification model,called ArcMargin,which incorporates metric learning into a convolutional neural network(CNN)to make the CNN model more discriminative.ArcMargin maps network traffic samples from the same category more closely while samples from different categories are mapped as far apart as possible.The metric learning regularization feature is called additive angular margin loss,and it is embedded in the object function of traditional CNN models.The proposed ArcMargin model is validated with three datasets and is compared with several other related algorithms.According to a set of classification indicators,the ArcMargin model is proofed to have better performances in both network traffic classification tasks and open-set tasks.Moreover,in open-set tasks,the ArcMargin model can cluster unknown data classes that do not exist in the previous training dataset.

Optimization Scheme of Trusted Task Offloading in IIoT Scenario Based on DQN

With the development of the Industrial Internet of Things(IIoT),end devices(EDs)are equipped with more functions to capture information.Therefore,a large amount of data is generated at the edge of the network and needs to be processed.However,no matter whether these computing tasks are offloaded to traditional central clusters or mobile edge computing(MEC)devices,the data is short of security and may be changed during transmission.In view of this challenge,this paper proposes a trusted task offloading optimization scheme that can offer low latency and high bandwidth services for IIoT with data security.Blockchain technology is adopted to ensure data consistency.Meanwhile,to reduce the impact of low throughput of blockchain on task offloading performance,we design the processes of consensus and offloading as a Markov decision process(MDP)by defining states,actions,and rewards.Deep reinforcement learning(DRL)algorithm is introduced to dynamically select offloading actions.To accelerate the optimization,we design a novel reward function for the DRL algorithm according to the scale and computational complexity of the task.Experiments demonstrate that compared with methods without optimization,our mechanism performs better when it comes to the number of task offloading and throughput of blockchain.

Blockchain-Based Flexible Double-Chain Architecture and Performance Optimization for Better Sustainability in Agriculture

Blockchain is an emerging decentralized distributed technology that can cross the boundaries and guarantee safe and trustworthy value transfers between participants.Combining the blockchain technology with the Internet of Things(IoT)technology to enhance the transparency and sustainability of agricultural supply chains,has attracted researchers from both academia and industry.This paper reviews the latest applications of the blockchain and IoT technologies in the sustainable agricultural supply chain management and explores the design and implementation of a blockchain-based sustainable solution.By placing the sustainable agricultural supply chain management at its core,a blockchain-based framework is designed.Considering the heterogeneity of the transaction data and the IoT data,the openness of sustainability information and the sensitivity of participants’data,a double-chain structure is proposed including the consensus method,the transaction mechanisms,the sustainability assessment method and the performance optimization strategy.The sustainable management practices of all participants are introduced into the blockchain network,especially those allowing the government to play a more signicant role in agriculture supply management.Meanwhile,to meet the scenario requirements,a data reduction method is designed to improve performance and reduce block size.Simulations are performed to evaluate the latency,throughput,costs and efciency of the proposed structure.This paper can be a useful reference for further research on the application of blockchain and IoT technologies in sustainable agricultural management.

Effects of arginine replacement with L-citrulline on the arginine/nitric oxide metabolism in chickens:An animal model without urea cycle

Background This study examined the efficacy of L-citrulline supplementation on the arginine/nitric oxide metabolism,and intestinal functions of broilers during arginine deficiency.A total of 288 day-old Arbor Acre broilers were randomly assigned to either an arginine deficient basal diet(NC diet),NC diet+0.50%L-arginine(PC diet),or NC diet+0.50%L-citrulline(NCL diet).Production performance was recorded,and at 21 days old,chickens were euthanized for tissue collection.Results The dietary treatments did not affect the growth performance of broilers(P>0.05),although NC diet increased the plasma alanine aminotransferase,urate,and several amino acids,except arginine(P<0.05).In contrast,NCL diet elevated the arginine and ornithine concentration higher than NC diet,and it increased the plasma citrulline greater than the PC diet(P<0.05).The nitric oxide concentration in the kidney and liver tissues,along with the plasma and liver e NOS activities were promoted by NCL diet higher than PC diet(P<0.05).In the liver,the activities of arginase 1,ASS,and ASL,as well as,the gene expression of i NOS and OTC were induced by PC diet greater than NC diet(P<0.05).In the kidney,the arginase 1,ASS and ASL enzymes were also increased by PC diet significantly higher than the NC and NCL diets.Comparatively,the kidney had higher abundance of n NOS,ASS,ARG2,and OTC genes than the liver tissue(P<0.05).In addition,NCL diet upregulated(P<0.05)the m RNA expression of intestinal nutrient transporters(EAAT3 and PEPT1),tight junction proteins(Claudin 1 and Occludin),and intestinal mucosal defense(MUC2 and p Ig R).The intestinal morphology revealed that both PC and NCL diets improved(P<0.05)the ileal VH/CD ratio and the jejunal VH and VH/CD ratio compared to the NC fed broilers.Conclusion This study revealed that NCL diet supported arginine metabolism,nitric oxide synthesis,and promoted the intestinal function of broilers.Thus,L-citrulline may serve as a partial arginine replacement in broiler’s diet without detrimental impacts on the performance,arginine metabolism and gut health of chickens.

Robust Virtual Network Embedding Based on Component Connectivity in Large-Scale Network

Virtual network embedding problem which is NP-hard is a key issue for implementing software-defined network which is brought about by network virtualization. Compared with other studies which focus on designing heuristic algorithms to reduce the hardness of the NP-hard problem we propose a robust VNE algorithm based on component connectivity in large-scale network. We distinguish the different components and embed VN requests onto them respectively. And k-core is applied to identify different VN topologies so that the VN request can be embedded onto its corresponding component. On the other hand, load balancing is also considered in this paper. It could avoid blocked or bottlenecked area of substrate network. Simulation experiments show that compared with other algorithms in large-scale network, acceptance ratio, average revenue and robustness can be obviously improved by our algorithm and average cost can be reduced. It also shows the relationship between the component connectivity including giant component and small components and the performance metrics.

Formal Semantics of OWL-S with Rewrite Logic

SOA is built upon and evolving from older concepts of distributed computing and modular programming, OWL-S plays a key role in describing behaviors of web services, which are the essential of the SOA software. Although OWL-S has given semantics to concepts by ontology technology, it gives no semantics to control-flow and data-flow. This paper presents a formal semantics framework for OWL-S sub-set, including its abstraction, syntax, static and dynamic seman-tics by rewrite logic. Details of a consistent transformation from OWL-S SOS of control-flow to corresponding rules and equations, and dataflow semantics including “Precondition”, “Result” and “Binding” etc. are explained. This paper provides a possibility for formal verification and reliability evaluation of software based on SOA.

Dietary L-citrulline supplementation modulates nitric oxide synthesis and antioxidant status of laying hens during summer season

Background:L-citrulline(L-Cit),a non-protein amino acid,has been implicated in several physiological functions including anti-inflammatory,anti-oxidative,and hypothermic roles,however,there is a paucity of information with regards to its potential in poultry production.Methods:This study was designed to investigate the effects of dietary L-Cit supplementation on the production performance,nitric oxide production,and antioxidant status of laying hens during summer period.Hy-Line Brown laying hens(n=288,34 weeks old)were allotted to four treatment,6 replicates of 12 chickens each.Dietary treatments of control(basal diets),0.25%,0.50%and 1.00%L-Cit supplementation were fed to chickens for eight(8)weeks.Production performance,free amino acid profiles,nitric oxide production,and antioxidant properties were measured.Blood samples were collected at the 4th and 8th weeks of the experiment.Results:Air temperature monitoring indicated an average daily minimum and maximum temperatures of 25.02°C and 31.01°C respectively.Dietary supplementation with L-Cit did not influence(P>0.05)the production performance,and rectal temperature of laying hens.Egg shape index was increased(P<0.05)with increasing levels of L-Cit.Serum-free content of arginine,citrulline,ornithine,tryptophan,histidine,GABA,and cystathionine were elevated,but taurine declined with L-Cit diets.Plasma nitric oxide(NOx)concentration was highest at 1%L-Cit.Likewise,nitric oxide synthase(NOS)activity for total NOS(tNOS)and inducible NOS(iNOS)were upregulated with increasing L-Cit levels,although,tNOS was not affected at the 4th week.Anti-oxidant enzymes including catalase and superoxide dismutase(SOD)were increased with L-Cit supplementation,however,SOD activity was unchanged at 4th week,while total anti-oxidant capacity increased at the 8th week.L-Cit supplementation attenuated the extent of lipid peroxidation,and also inhibited glutathione peroxidase activity.Conclusion:Dietary L-Cit supplementation modulated systemic arginine metabolism,nitric oxide synthesis,antioxidant defense system,and increased the egg shape index of laying hens during the summer season.1%L-Cit supplementation proved most effective in potentiating these effects and may be adopted for feed formulation strategies.