Unveiling the emerging role of curcumin to alleviate ochratoxin A-induced muscle toxicity in grass carp(Ctenopharyngodon idella):in vitro and in vivo studies

Background Ochratoxin A(OTA),a globally abundant and extremely hazardous pollutant,is a significant source of contamination in aquafeeds and is responsible for severe food pollution.The developmental toxicity of OTA and the potential relieving strategy of natural products remain unclear.This study screened the substance curcumin(Cur),which had the best effect in alleviating OTA inhibition of myoblast proliferation,from 96 natural products and investigated its effect and mechanism in reducing OTA myotoxicity in vivo and in vitro.Methods A total of 720 healthy juvenile grass carp,with an initial average body weight of 11.06±0.05 g,were randomly assigned into 4 groups:the control group(without OTA and Cur),1.2 mg/kg OTA group,400 mg/kg Cur group,and 1.2 mg/kg OTA+400 mg/kg Cur group.Each treatment consisted of 3 replicates(180 fish)for 60 d.Results Firstly,we cultured,purified,and identified myoblasts using the tissue block culture method.Through preliminary screening and re-screening of 96 substances,we examined cell proliferation-related indicators such as cell viability and ultimately found that Cur had the best effect.Secondly,Cur could alleviate OTA-inhibited myoblast differentiation and myofibrillar development-related proteins(Myo G and MYHC)in vivo and in vitro and improve the growth performance of grass carp.Then,Cur could also promote the expression of OTA-inhibited protein synthesis-related proteins(S6K1 and TOR),which was related to the activation of the AKT/TOR signaling pathway.Finally,Cur could downregulate the expression of OTA-enhanced protein degradation-related genes(murf1,foxo3a,and ub),which was related to the inhibition of the Fox O3a signaling pathway.Conclusions In summary,our data demonstrated the effectiveness of Cur in alleviating OTA myotoxicity in vivo and in vitro.This study confirms the rapidity,feasibility,and effectiveness of establishing a natural product screening method targeting myoblasts to alleviate fungal toxin toxicity.

Reproductive height determines the loss of clonal grasses with nitrogen enrichment in a temperate grassland

Tall clonal grasses commonly display competitive advantages with nitrogen(N)enrichment.However,it is currently unknown whether the height is derived from the vegetative or reproductive module.Moreover,it is unclear whether the height of the vegetative or reproductive system regulates the probability of extinction and colonization,and determines species diversity.In this study,the impacts on clonal grasses were studied in a field experiment employing two frequencies(twice a year vs.monthly)crossing with nine N addition rates in a temperate grassland,China.We found that the N addition decreased species frequency and increased extinction probability,but did not change the species colonization probability.A low frequency of N addition decreased species frequency and colonization probability,but increased extinction probability.Moreover,we found that species reproductive height was the best index to predict the extinction probability of clonal grasses in N-enriched conditions.The low frequency of N addition may overestimate the negative effect from N deposition on clonal grass diversity,suggesting that a higher frequency of N addition is more suitable in assessing the ecological effects of N deposition.Overall,this study illustrates that reproductive height was associated with the clonal species extinction probability under N-enriched environment.

Effect of Using Israel Napier Grass in Feed Ration on Growth Performance of Local Chicken of Cambodia

This study investigated the effect of Israel grass in feed formulation on growth performance of local chicken.The study was conducted from October 2023 until January 2024 in Kampong Chheutel Institute of Technology.The CRD(Completely Randomized Design)was used with 4 treatments and 4 replications.The local chicks were purchased from local famer at 1 day old and kept in whole pen by feeding commercial feed.At 21 days old the total 320 chicks were allocated into experimental treatments.The 4 feed formulas based on the level of Israel grass added such as 0,5%,7%and 9%,were called T1(control),T2,T3 and T4 respectively.The result showed that body weight gain,feed intake,ADG(Average Daily Gain)and FCR(Feed Conversion Ratio)in all treatments were not significantly different(p>0.05).However,there was strong correlation between living weight with carcass of al treatments,but no difference among carcass percentage of local chicken for all different diet in this study.In conclusion,the Israel grass did not affect growth performance of local chickens and can be used to replace some expensive feed ingredient,such as rice bran.

Camalote Grass (Paspalum fasciculatum Willd) as a Sustainable Raw Material for the Production of Lignocellulosic Ethanol

The current trend of replacing a percentage of gasoline with ethanol has promoted the development of new processes for its production from lignocellulosic biomass. This work reports the production of ethanol from the Camalote grass (Paspalum fasciculatum Willd). The lignocellulosic biomass was subjected to acid hydrolysis at 125C and 15 psi with H2SO4 concentrations at 5%, 10%, and 20%, obtaining an average of reducing sugars (pentoses and hexoses) from the hydrolyzed juice with 12.3%, 10%, and 17% Brix, respectively. The sugars were fermented using yeast of the Saccharomyces cerevisiae at 30C for 48 hours. Finally, the ethanol was distilled at 78C, and the average yields were obtained through analysis of variance with a 95% confidence level. The values indicate that there is a significant difference (p > 0.05), the Tukey study shows that all the % v/v averages are different from each other. For H2SO4 concentration at 5% (10.33 ± 2), H2SO4 at 10% (9.33 ± 1.8), and H2SO4 at 20% (6.33 ± 2). The acidity analysis for the ethanol obtained from each treatment gave a value of 1.8 mg/L of acetic acid in all cases.

Decoding the Genetic Blueprint of Grass Skyscrapers

In the lush forests of Asia,towering bamboos stand tall,defying the folk expectations for grassy plants.These woody giants,some reaching the staggering height of nearly 40 meters,are the world’s largest members of the grass family.

Dietary protein levels changed the hardness of muscle by acting on muscle fiber growth and the metabolism of collagen in sub-adult grass carp(Ctenopharyngodon idella)

Background:Nutrient regulation has been proven to be an effective way to improve the flesh quality in fish.As a necessary nutrient for fish growth,protein accounts for the highest proportion in the fish diet and is expensive.Although our team found that the effect of protein on the muscle hardness of grass carp was probably related to an increased collagen content,the mechanism for this effect has not been deeply explored.Moreover,few studies have explored the protein requirements of sub-adult grass crap(Ctenopharyngodon idella).Therefore,the effects of different dietary protein levels on the growth performance,nutritional value,muscle hardness,muscle fiber growth,collagen metabolism and related molecule expression in grass carp were investigated.Methods:A total of 450 healthy grass carp(721.16±1.98 g)were selected and assigned randomly to six experimen-tal groups with three replicates each(n=25/replicate),and were fed six diets with 15.91%,19.39%,22.10%,25.59%,28.53%and 31.42%protein for 60 d.Results:Appropriate levels of dietary protein increased the feed intake,percentage weight gain,specific growth rate,body composition,unsaturated fatty acid content in muscle,partial free amino acid content in muscle,and muscle hardness of grass carp.These protein levels also increased the muscle fiber density,the frequency of new muscle fibers,the contents of collagen and IGF-1,and the enzyme activities of prolyl 4-hydroxylases and lysyloxidase,and decreased the activity of matrix metalloproteinase-2.At the molecular level,the optimal dietary protein increased col-lagen type Iα1(Colα1),Colα2,PI3K,Akt,S6K1,La ribonucleoprotein domain family member 6a(LARP6a),TGF-β1,Smad2,Smad4,Smad3,tissue inhibitor of metalloproteinase-2,MyoD,Myf5,MyoG and MyHC relative mRNA levels.The levels of the myostatin-1 and myostatin-2 genes were downregulated,and the protein expression levels of p-Smad2,Smad2,Smad4,p-Akt,Akt,LARP6 and Smad3 were increased.Conclusions:The appropriate levels of dietary protein promoted the growth of sub-adult grass carp and improved muscle hardness by promoting the growth of muscle fibers,improving collagen synthesis and depressing collagen degradation.In addition,the dietary protein requirements of sub-adult grass carp were 26.21%and 24.85%according to the quadratic regression analysis of growth performance(SGR)and the muscle hardness(collagen content),respectively.

Mannan oligosaccharides alleviate oxidative injury in the head kidney and spleen in grass carp(Ctenopharyngodon idella)via the Nrf2 signaling pathway after Aeromonas hydrophila infection

Background Mannan oligosaccharides(MOS)are recommended as aquaculture additives owing to their excellent antioxidant properties.In the present study,we examined the effects of dietary MOS on the head kidney and spleen of grass carp(Ctenopharyngodon idella)with Aeromonas hydrophila infection.Methods A total of 540 grass carp were used for the study.They were administered six gradient dosages of the MOS diet(0,200,400,600,800,and 1,000 mg/kg)for 60 d.Subsequently,we performed a 14-day Aeromonas hydrophila challenge experiment.The antioxidant capacity of the head kidney and spleen were examined using spectrophotometry,DNA fragmentation,qRT-PCR,and Western blotting.Results After infection with Aeromonas hydrophila,400-600 mg/kg MOS supplementation decreased the levels of reactive oxygen species,protein carbonyl,and malonaldehyde and increased the levels of anti-superoxide anion,antihydroxyl radical,and glutathione in the head kidney and spleen of grass carp.The activities of copper-zinc superoxide dismutase,manganese superoxide dismutase,catalase,glutathione S-transferase,glutathione reductase,and glutathione peroxidase were also enhanced by supplementation with 400-600 mg/kg MOS.Furthermore,the expression of most antioxidant enzymes and their corresponding genes increased significantly with supplementation of 200-800 mg/kg MOS.mRNA and protein levels of nuclear factor erythroid 2-related factor 2 also increased following supplementation with 400-600 mg/kg MOS.In addition,supplementation with 400-600 mg/kg MOS reduced excessive apoptosis by inhibiting the death receptor pathway and mitochondrial pathway processes.Conclusions Based on the quadratic regression analysis of the above biomarkers(reactive oxygen species,malondialdehyde,and protein carbonyl)of oxidative damage in the head kidney and spleen of on-growing grass carp,the recommended MOS supplementation is 575.21,557.58,531.86,597.35,570.16,and 553.80 mg/kg,respectively.Collectively,MOS supplementation could alleviate oxidative injury in the head kidney and spleen of grass carp infected with Aeromonas hydrophila.

Implications of vitamin D for flesh quality of grass carp(Ctenopharyngodon idella):antioxidant ability,nutritional value,sensory quality,and myofiber characteristics

Background Muscle represents a unique and complex system with many components and comprises the major edible part of animals.Vitamin D is a critical nutrient for animals and is known to enhance calcium absorption and immune response.In recent years,dietary vitamin D supplementation in livestock has received increased attention due to biological responses including improving shear force in mammalian meat.However,the vitamin D acquisition and myofiber development processes in fish differ from those in mammals,and the effect of vitamin D on fish flesh quality is poorly understood.Here,the influence of dietary vitamin D on fillet quality,antioxidant ability,and myofiber development was examined in grass carp(Ctenopharyngodon idella).Methods A total of 540 healthy grass carp,with an initial average body weight of 257.24±0.63 g,were allotted in 6 experimental groups with 3 replicates each,and respectively fed corresponding diets with 15.2,364.3,782.5,1,167.9,1,573.8,and 1,980.1 IU/kg vitamin D for 70 d.Results Supplementation with 1,167.9 IU/kg vitamin D significantly improved nutritional value and sensory quality of fillets,enhancing crude protein,free amino acid,lipid,and collagen contents;maintaining an ideal pH;and reduc-ing lactate content,shear force,and cooking loss relative to respective values in the control(15.2 IU/kg)group.Average myofiber diameter and the frequency of myofibers>50μm in diameter increased under supplementation with 782.5–1,167.9 IU/kg vitamin D.Levels of oxidative damage biomarkers decreased,and the expression of antioxi-dant enzymes and nuclear factor erythroid 2-related factor 2 signaling molecules was upregulated in the 1,167.9 IU/kg vitamin D treatment compared to respective values in the control group.Furthermore,vitamin D supplementation activated cell differentiation by enhancing the expression of myogenic regulatory factors and myocyte enhancer factors compared to that in the control group.In addition,supplementation with 1,167.9 IU/kg vitamin D improved protein deposition associated with protein synthesis molecule(target of rapamycin)signaling and vitamin D receptor paralogs,along with inhibition of protein degradation(forkhead box protein 1)signaling.Conclusions Overall,the results demonstrated that vitamin D strengthened antioxidant ability and myofiber devel-opment,thereby enhancing nutritional value and sensory quality of fish flesh.These findings suggest that dietary vitamin D supplementation is conducive to the production of nutrient-rich,high quality aquaculture products.

Sporting Usefulness Potential of Nine Local Taxa of Grasses for Lawns in the Agro-Ecological Zone with Bimodal Rainfall in Cameroon

The Cameroonian flora has a very high biodiversity that remains largely unexplored. It contains many grasses that can be used for sports lawns, but are currently underutilized. In order to contribute to the improvement of the quality of sports lawns, nine local grass taxa from the agro-ecological zone with bimodal rainfall in Cameroon were evaluated for their potential for sporting use in natural lawns. The method of the Study and Control Group for Varieties and Seeds was used to evaluate the sports lawn characteristics of the taxa. The resistance to trampling and pulling, the density of the lawn, and the aesthetic appearance, which are factors in calculating the sports index, were monitored at two sites, including the experimental space at the University of Yaounde 1 in the Center region and Kagnol 2 in the East region, from January 2017 to January 2020. The monthly lawn characteristic data allowed for the differentiation between the means and the determination of the sports index of the taxa compared to commercialized lawn varieties. The sports index of the evaluated taxa varied: Cynodon dactylon (6.989), Eleusine indica (6.338), Sporobolus natalensis (6.301), Cynodon cf Cynodon dactylon (6.257), Eragrostis tremula (5.939), Sporobolus pyramidalis (5.583), Agrostis rupestris (5.335), Axonopus compressus (4.991), and Digitaria sp. (4.544). These results show that these grass taxa have potential for sporting use in lawn mixtures at different levels of sports disciplines.

The Destruction of Diasporic White Individuals’Sense of Identity in The Grass is Singing

The importance of diaspora identity has grown in recent years as the world becomes more interconnected and diaspora individuals are increasingly involved in matters among different ethnics.The Grass is Singing by Doris Lessing is considered one of the most outstanding works of literature after World War II.Interest in ethnic identity has been heightened.The book is recognized as an introspective reflection of the spiritual crisis suffered by diaspora people and societal crises of the time.The thesis will examine the oppression imposed by dominant white group by exploring the transformation of diasporic white individuals’identity.

生草对山核桃林地土壤微生物群落结构和多样性的影响

山核桃林下设置3种人工生草(油菜、绵枣儿、野豌豆)及清耕(对照)4个处理,种植4年后,采用高通量测序技术分析各处理土壤微生物群落结构及多样性,研究不同处理微生物与环境因子关联性。结果表明:山核桃林下不同生草处理占优势地位的土壤细菌群落为酸杆菌门和变形菌门,油菜处理上层(0~10 cm)土壤较下层(20~40 cm)变形菌门的相对丰度提高71.41%;各生草处理占优势地位的真菌群落为子囊菌门、担子菌门和球囊菌门,上层(0~10 cm)土壤球囊菌门相对丰度较对照分别提高202.81%、193.90%、65.04%,各生草处理上层土壤细菌群落物种组成均匀度较高且物种丰富,油菜处理上层土壤Chao1、Shannon、Ace指数显著高于其他生草处理。土壤真菌群落的多样性指数各处理间均未达到显著性差异。树状聚类图显示,不同生草处理对土壤的细菌、真菌群落均具有显著的影响。基于门水平下土壤群落结构和环境因子的典范对应分析(CCA)可知,细菌群落结构与pH、全磷、有效磷呈极显著正相关,与有机质呈显著正相关;真菌群落结构与pH呈极显著正相关,与全磷、有效磷、过氧化氢酶呈显著正相关。这说明不同生草处理对山核桃林地土壤微生物影响较大,选择适宜的生草种类可改善土壤微生物群落结构,提高细菌群落物种组成均匀度及丰富度,其中油菜综合效果最好。

“平台”与我国县域基层法治秩序的生成——浙江海宁社会治理实践的观察

基层社会治理“平台”是我国县域范围构建具有中国特色法治秩序的重要实践形式。在提升县域基层社会治理水平的过程中,平台被打造成一个由不同政府机构、不同社会组织与社会成员通过协调、协商、议论等方式博弈以解决与民生密切相关的各种类型问题的工作机制,客观上已经助力生成了法治秩序不可或缺的不同主体之间展开话语交流的公共空间。在浙江海宁,平台被用于促进实现公众与企业合法权利、改造和规范行使公共权力、保障社会稳定与居民安居乐业,以公开促公正公平,有效提升了法律在基层的实施能力。在法治建设正在寻求新的突破之际,有关平台建设的实践具有一定的可借鉴的普遍意义。

天山北坡平原荒漠灌区9个紫花苜蓿品种生产性能综合评价

【目的】筛选出适宜在天山北坡平原荒漠区推广种植的紫花苜蓿品种。【方法】采用单因素随机区组设计,测定9个紫花苜蓿品种的株高、草产量、品质等指标,并利用灰色关联法对9个品种进行综合评价。【结果】随种植年限增加,供试材料的鲜草和干草产量均呈下降趋势,其中第1年的干草产量占比较高,平均为37.77%;佰苜341的株高积累量最大,为939.8 cm,显著高于其他品种;骑士T干草总产量、粗蛋白含量和相对饲喂价值最高,分别为61602.03 kg/hm^(2)、16.83%和119.16%;灰色关联度综合评价结果由高到低的顺序为:骑士T>佰苜202>大银河>阿迪娜>佰苜341>佰苜371>挑战者>佰苜401>康赛。【结论】骑士T的综合表现较好,建议在天山北坡平原荒漠灌区引种种植。

自动巡航草方格固沙机结构设计分析及试验

针对荒漠化治理对草方格固沙机的需求,提出了一种集底盘、开沟机构、草箱机构、插草机构、覆压沙机构、播种及洒水机构、升降机构与一体的多功能草方格固沙机。分析了“T+一”式草方格种植模式的优势,提出了自动巡航草方格固沙机整体结构方案,并对开沟机构、草箱机构、插草机构、覆压沙机构、播种及洒水机构、升降机构等关键组件的功能和结构进行了详细分析。应用三维建模软件建立虚拟机构模型,对推草和插草机构进行了运动仿真分析,并对整机进行了作业性能试验。结果表明:各机构构件间无干涉,构件运动仿真轨迹符合功能要求,杆件尺寸参数设计合理,机器作业效率高,可有效保证草方格铺设的准确性和有效性,满足机械化固沙的要求,具有良好的通用性和适应性。

牧草太空育种的研究现状与展望

【目的】牧草太空育种是近三十年来新兴的一种育种技术,具有变异多、变幅大、稳定快等特点,可缩短牧草育种周期。本文综述了太空育种的研究现状,分析总结了太空育种的原理、方法及可能存在的问题,以期为今后牧草太空育种提供更多参考和启发。【方法】通过Web of Science、Google Scholar、中国知网、百度学术等网站查阅了大量太空育种尤其是牧草太空育种的相关文献,并对文献资料进行收集、分析和整理。【结果】太空环境诱变是当今牧草育种重要发展方向之一,通过总结太空诱变技术在牧草育种中的应用,分析了牧草太空育种中面临的问题和挑战,展望了采用太空环境诱变创制牧草新品种的前景。【结论】太空环境诱变能诱发牧草基因组中的突变,增加其遗传多样性,从而创造出具有新特性的植物品种,对牧草类作物进行种质资源的创制具有重大意义,同时也为快速培育优良牧草新品种及特异种质资源开辟了一条新途径。太空育种技术为牧草育种开辟了新的可能性,有望成为未来太空农业的重要组成部分。

基层应急治理共同体的塑造--基于信任—规则—行动力的框架分析

构建基层应急治理共同体,提升基层应急治理能力,是推进国家治理体系和治理能力现代化的重要组成部分。目前基层应急治理面临着基层政府治理能力不足、体制机制不畅、公众参与不足和社会组织参与无序性等问题,亟须缩短应急处突的链条,提高决策的适应性,构建共建、共治、共享的基层应急治理共同体。在共同体塑造过程中,通过构建“信任—规则—行动力”的框架,在党建引领下,以信任价值塑造公共精神,以规则建构推进契约共建,以在地文化环境建构和能力提升的系统工程推动应急治理共同体的行动力塑造,将共同体的功能贯穿于风险研判、处置、应对、恢复于一体的全周期应急治理动态机制中,推动应急治理走向人人有责、人人尽责、人人享有的治理格局。

饲草附生乳酸菌对碳源的选择性

【目的】探究饲草源乳酸菌对碳源的选择性,为不同草种筛选适宜的青贮菌种。【方法】选取饲草中分离获得的16株代表性乳酸菌作为研究对象,在MRS液体培养基中以葡萄糖、蔗糖、果糖、木糖、棉籽糖以及5种糖混合为碳源,进行不同菌株发酵培养。每株乳酸菌设3个重复,每个糖处理设空白对照(不接菌)。采用高效液相色谱仪测定各处理发酵24 h后液体培养基中剩余碳源含量和乳酸产量。【结果】(1)蔗糖是大部分菌株发酵首选碳源,在棉籽糖、葡萄糖、果糖和木糖的选择上不同菌株差异较大,发酵乳杆菌(Lactobacillus fermentum,LbFWM)首选棉籽糖和木糖,假肠膜明串珠菌(Leuconostioc pseudomesenteroides,LeP-IR)首选木糖。(2)罗伊氏乳杆菌(Lactobacillus reuteri,LbR-EG)和柠檬明串珠菌(Leuconostoc citreum,LeC-IR)对蔗糖,LbF-WM和LbR-EG对果糖,LbF-WM、LbR-EG和LeP-IR对棉籽糖的利用率均达100%,屎肠球菌(Enterococcus faecium,EF-KG)、短乳杆菌(Lactobacillus brevis,LbB-KG)、戊糖乳杆菌(Lactobacillus pentosus,LbPe-EG)、乳酸乳球菌(Lactococcus lactis,LcL-SC)对葡萄糖的利用率高于其他碳源。(3)灰黄色肠球菌(Enterococcus durans,EG-IR)利用葡萄糖和混合糖,LbPe-EG利用果糖,肠膜明串珠菌(Leuconostoc mesenteroides,LeM-IR)利用棉籽糖和混合糖,LbPe-EG利用蔗糖,LbF-WM利用木糖,格氏乳球菌(Lactococcus garvieae,LcG-IR)利用混合糖发酵乳酸产量最高。(4)耐久肠球菌(Enterococcus durans,ED-IR)利用葡萄糖,植物乳杆菌(Lactobacillus plantarum,LbPl-IR)、LbPe-EG利用果糖,LbPl-IR和LeM-IR利用棉籽糖,LbPe-EG、LbPl-IR和ED-IR利用蔗糖,LeP-IR利用木糖,LcG-IR和EG-IR利用混合糖产乳酸效率较高。LbPl-IR在5种单糖中产酸效率均达80%以上。【结论】不同菌株对同一碳源的利用率、产酸量和产酸效率均不同;同一株菌株对不同碳源的利用率、产酸量和产酸效率也不相同。其中,蔗糖为大部分菌株的首选碳源,蔗糖和葡萄糖的利用率和产乳酸量较高,葡萄糖的产酸效率较高;青贮调制时,可针对饲草中分布乳酸菌种类选择最适碳源。

烯效唑对扁穗雀麦生长发育和种子产量品质的影响

探究烯效唑对扁穗雀麦生长发育和种子产量品质的影响,为其种子增产提质提供科学依据。以‘江夏’扁穗雀麦为试验材料,采取随机区组设计,在拔节期喷施不同浓度烯效唑(0、50、90、130 mg/kg),研究植株生长、种子产量和萌发特性。结果表明:烯效唑降低了植株高度,提高了抗倒伏能力。除50 mg/kg的烯效唑对生殖枝数有显著增加外(P<0.05),其余处理对植株第二节长、茎粗、分蘖数和生殖枝数影响差异不显著。喷施不同浓度烯效唑,扁穗雀麦的小穗数/生殖枝、种子数和种子产量均表现为增加,但只有50 mg/kg处理下各指标差异达显著水平(P<0.05)。90 mg/kg烯效唑处理可显著增加扁穗雀麦种子活力指数(P<0.05),但所有处理对千粒重、发芽率和发芽指数影响较小。各指标相关性分析发现,植株高度与倒伏率、分蘖数和生殖枝数极显著正相关(P<0.01);种子产量和生殖枝数显著正相关(P<0.05)。喷施50 mg/kg烯效唑,扁穗雀麦种子产量最高,达1508.31 kg/hm^(2),较对照增加13.63%,差异显著(P<0.05)。

我国草原分区-分类-分级生态修复模式研究

草原是我国重要的自然资源和生态屏障,草原生态修复是我国生态文明建设的重要内容,也是提升草原生态系统服务功能和固碳潜力的重要途径。已有大量研究针对退化草原提出了多种有效的生态恢复措施,但缺乏系统性和针对性的总结。本文在系统梳理和总结国内外草原生态修复研究的基础上,基于文献计量学的研究方法,总结了我国草原生态修复经历的三个阶段。同时,针对不同区域、不同退化/受损/破坏类型和和不同退化程度的草原,探索和提出了我国草原分区-分类-分级生态修复模式,并对我国草原生态修复的未来发展提出了相关建议,以期为我国草原生态修复和可持续管理提供科学依据和参考。

氨基酸微量元素螯合物对草鱼肝脏和肠道健康的影响

为研究饲料中氨基酸微量元素螯合物(铁、锰、铜、锌)对草鱼(Ctenopharyngodon idellus)肝脏和肠道健康的影响。共设置6组等氮(30%)、等脂(4.7%)实验饲料,对照组(CON)为不添加铁、锰、铜、锌4种微量元素的基础饲料,在对照组配方基础上添加无机铁(50 mg/kg)、铜(2 mg/kg)、锰(10 mg/kg)、锌(40 mg/kg)制成IT100组,用氨基酸微量元素螯合物以25%(OT25组)、50%(OT50组)、75%(OT75组)和100%(OT100组)的比例替代IT100组中无机微量元素,投喂初始体质量(40.05±0.05) g的草鱼8周。研究显示,与对照组相比,饲料中添加无机微量元素和氨基酸微量元素螯合物显著提高了草鱼肝脏的谷胱甘肽过氧化物酶(GPx)、微量还原型谷胱甘肽(GSH)和总超氧化物歧化酶(SOD)活性,降低了丙二醛含量(P<0.05)。OT100组显著提高了过氧化氢酶(CAT)活性,且OT75组和OT100组GPx活性和GSH含量显著高于IT100组(P<0.05)。与对照组相比,各组草鱼的肝细胞形态和肝血窦丰度趋于正常。与对照组相比,除OT25组外,其余各组的肠道绒毛高度和杯状细胞数量显著提高,且OT75和OT100组显著高于IT100组。无机微量元素和氨基酸微量元素螯合物降低了草鱼肠道细胞因子白介素-6(il-6)和白介素-1β(il-1β)基因表达量,提高了肠道紧密连接蛋白闭锁小带蛋白-2(zo-2)和claudin12基因表达量。OT75组显著提高了zo-1和occludin基因表达量,且OT75组il-1β基因表达量显著低于IT100组。综上所述,无机微量元素和氨基酸微量元素螯合物均可显著改善草鱼肠道和肝脏健康,75%氨基酸微量元素螯合物的作用效果显著优于无机微量元素。