精料补饲水平对早期断奶山羊生长性能和血清生化指标的影响

本试验旨在研究精料补饲水平对早期断奶山羊牛长性能和血清生化指标的影响.试验选用32只(35±3)日龄早期断奶简阳大耳羊山羊[(8.576±1.831)kg BW],公母各占1/2,根据体重采用随机区组试验设计,将山羊分为4个组,每组8只(公母各占1/2),单栏单饲.对照组跟随母羊哺乳,试验Ⅰ、Ⅱ和Ⅲ组在35日龄实施断奶,分别补饲50、150和250 g/d精料.试验期42 d.试验结果表明:1)补饲精料对断奶山羊的平均日增重有显著或极显著影响(P<0.05或P<0.01).其中,250 g/d组平均日增重最高,较对照组提高了83.80%(P<0.01);50 g/d组平均日增重最低,显著或极显著低于其他各组(P<0.05或P<0.01).试验组间粗料采食量差异不显著(P>0.05).试验组山羊总料重比差异不显著(P>0.05);但按摄入精料计算,150、250 g/d组料(精料)重比极显著高于50 g/d组(P<0.01).2)250、150 g/d组山羊总干物质、消化能、粗蛋白质摄入量极显著高于50 g/d组(P<0.01),各试验组的饲粮总的中性洗涤纤维和酸性洗涤纤维摄入量差异不显著(P>0.05).3)各组山羊血清总蛋白、白蛋白、血浆尿素氮、血清IgA和IgM差异不显著(P>0.05).由此说明,补饲精料有利于提高早期断奶大耳羊山羊的营养物质摄入量,促进生长.补饲精料量(250 g/d)占食入饲料总量的(70.0±3.0)%时,可极显著提高山羊的生长性能.     

海南原鸡PDCD10的克隆、表达及其蛋白的生物信息学分析

通过克隆、表达海南原鸡程序性细胞死亡分子10(Programmed cell death10,PDCD10)基因,对其蛋白进行生物信息学分析。采用RT-PCR方法克隆得到海南原鸡PDCD10基因CDS区,将扩增产物与原核表达载体pET42a连接,构建pET42a-PDCD10重组质粒,经IPTG诱导表达后,进行SDS-PAGE和Western blot分析;运用生物信息学软件对所获得基因的核苷酸序列进行分析,并预测其编码蛋白的理化性质及二级结构等。克隆获得了PDCD10639bp的CDS区核苷酸序列,融合蛋白分子量约为57ku,生物信息学分析发现,PDCD10CDS区包括1个639bp的开放读码框,编码212个氨基酸。该蛋白不含信号肽,无跨膜区,二级结构中存在大量α-螺旋。研究结果为进一步开展海南原鸡PDCD10的功能研究奠定了坚实的基础。     

脱氧雪腐镰刀菌烯醇对猪毒害作用及毒理机制研究进展

脱氧雪腐镰刀菌烯醇(deoxynivalenol, DON)是一种常见的污染粮食、饲料和食品的霉菌毒素,严重影响人和牲畜的健康。猪对DON非常敏感,DON可造成猪拒食、生长抑制、呕吐以及器官损伤、细胞毒性、免疫毒性等毒害作用。本文主要综述了DON对猪的毒害作用、毒理机制以及解毒剂开发等方面的研究进展,尤其关注DON毒理作用的遗传调控研究,旨在为从遗传本质提高猪对脱氧雪腐镰刀菌烯醇的抵抗力提供更全面的参考。     

酸枣仁提取物的生物学作用及其在畜牧生产中的应用

酸枣仁提取物是镇静安神的传统中药,其发挥生物学功能的主要成分是其中的皂苷和黄酮类。该提取物逐步受到中兽医的关注,在畜牧生产中有着广泛的开发利用前景。作者主要综述酸枣仁提取物对中枢神经系统、免疫系统及其在畜牧生产中应用的影响,为其在畜牧生产中的开发应用提供依据。     

O型口蹄疫病毒VP1 T细胞与B细胞表位基因双拷贝串联表达产物的免疫应答

以一株O型口蹄疫病毒(FMDV)外壳蛋白VP1基因为模板,合成与细胞免疫及体液免疫相关抗原表位肽基因:21-40肽(20AA)和141-160肽(20AA)基因序列,运用基因工程技术构建了含有串联结构21-40(20AA)～141-160(20AA)～21-40(20AA)～141-160(20AA)的2020-2020VP1融合基因表达载体r2020-2020,转化宿主菌BL21(DE3)RIL后诱导表达,表达产物经SDS-PAGE及Western Blot分析显示重组融合蛋白的分子量约为18Ku.动物实验表明,较小剂量的融合蛋白就能诱导豚鼠产生特异性T淋巴细胞增殖反应及抗FMDV中和抗体,证明该融合蛋白可同时激活细胞免疫及体液免疫反应,具有开发成为抗FMDV疫苗的应用价值.     

实验性脾虚证大鼠肝脏和肌肉组织中糖原变化的组织学观察

将45只大白鼠随机分成对照组、脾虚模型组及治疗组,每组15只。以利血平(1mg/kg·d)复制大白鼠脾虚证模型,四君子汤辅助治疗,在实验进行至第7天和第14天分别捕杀各组大白鼠,取肝脏、肌肉组织,用组织化学方法测定在不同组间和不同实验阶段其中糖原的变化。结果,在第7天时,脾虚组和治疗组糖原含量明显低于正常对照组,第14天时,与正常对照组相比较,脾虚组和治疗组糖原含量显著升高,且脾虚组糖原含量较其它两组高,提示肝脏和肌肉组织中糖原的变化可能是脾虚证发生发展的重要指标。     

Evaluation of Joint Toxicity of Enrofloxacin and Three Antimicrobials on MRC-5 Cells

The aim of this study was to evaluate the combined toxicity of enrofloxacin with each of three antimicrobials (ciprofloxacin,florfenicol and sulfamethazine).MRC-5 cells were used as a cell model to simulate the damage of lung cells caused by mixed contamination of antimicrobials.Multiple concentration gradients and mixing ratios were set.CCK-8 method was used to determine the inhibition rate of cell growth caused by four antimicrobials and the inhibition rate of cell growth caused by enofloxacin mixed with three antimicrobials,respectively.Then Chou-Talalay method was used to fit the median effect plot and to calculate the combination index (CI) value.The results showed that the growth inhibition rates of MCR-5 cells caused by four single drugs went up in a step-like manner with the increase of drug concentration in the tested concentration range,among them,the growth inhibitory rate of MCR-5 cells by florfenicol was low (<4.5%).The combined toxicity of the three binary combinations showed a concentration-dependent and mixing-ratio dependence.Mixing enrofloxacin and ciprofloxacin showed synergistic toxicity (CI<1) on MRC-5 cells at high and middle concentration groups,and antagonistic toxicity (CI>1) at the very-low-concentration groups.Mixing ciprofloxacin and florfenicol mainly showed an inhibited toxicity (CI>1).Binary combination enrofloxacin and sulfamethazine might present either a synergistic joint toxicity (CI<1) or an antagonistic joint toxicity (CI>1) as the concentration and mixing ratio changing.This study showed that it was necessary to assess the combined toxicity of antimicrobials in the toxicity evaluation of antimicrobials.Using Chou-Talalay method,the joint toxicity of multiple antimicrobials could be quickly and efficiently determined at cellular level.     

克氏原螯虾在安康地区三种养殖条件下生长情况的比较

为了引进和推广克氏原螯虾养殖技术,于2007年9月、10月分别从湖北购入亲虾和幼虾在安康水产试验示范站进行水泥池、稻田和土池塘三种条件下养殖;于2008年5月每周或半周测量一次体长体重,分别进行体长体重关系、个体出现率、个体相对增重率和体重体长比值的分析。结果表明：1.稻田克氏原螯虾体长体重的关系为：雌虾,y=0.0184x3.1984,R2=0.9506,雄虾,y=0.0113x3.4626,R2=0.9611,且雌虾生长匀速,雄虾生长异速,符合体重体长形态参数y=a＊Lb;2根据个体出现率可知,水泥池和稻田生长的群体主要集中7.71cm-9.71cm之间,土池塘生长的群体主要集中在8.21cm-10.71cm之间,土池塘生长速度相对较快;根据生长集中区间的个体相对增重率可知,5月份稻田个体增重率最高,为24.13%,土池塘最低;体重、体长比值随着体长的变化趋势表明,稻田虾呈线性变化,水泥池和土池塘虾变化呈“S”型,趋向线性变化。可以认为,克氏原螯虾可在安康地区正常生长,且本试验条件下5月份稻田中克氏原螯虾生长最快。     

Association between porpoise presence and fish choruses: implications for feeding strategies and ecosystem-based conservation of the East Asian finless porpoise

The associations between feeding activities and environmental variables inform animal feeding tactics that maximize energetic gains by minimizing energy costs while maximizing feeding success. Relevant studies in aquatic animals, particularly marine mammals, are scarce due to difficulties in the observation of feeding behaviors in aquatic environments. This data scarcity concurrently hinders ecosystem-based fishery management in the context of small toothed-cetacean conservation. In the present study, a passive acoustic monitoring station was deployed in an East Asian finless porpoise habitat in Laizhou Bay to investigate potential relationships between East Asian finless porpoises and their prey. The data revealed that porpoises were acoustically present nearly every day during the survey period. Porpoise detection rates differed between spring and autumn in concert with activities of fish choruses. During spring, fish choruses were present throughout the afternoon, and this was the time when porpoise vocalizations were the most frequently detected. During autumn, when fish choruses were absent, porpoise detection rates decreased, and diurnal patterns were not detected. The close association between fish choruses and finless porpoise activities implies an “eavesdropping” feeding strategy to maximize energetic gains, similar to other toothed cetaceans that are known to engage similar feeding strategies. Underwater noise pollution, particularly those masking fish choruses, could interrupt finless porpoises’ feeding success. Fisheries competing soniferous fishes with finless porpoise could impact finless porpoise viability through ecosystem disruption, in addition to fishing gear entanglement.     

野猪源奇异变形杆菌的分离鉴定及致病性分析

为探究贵州省野猪携带病原菌情况,本试验对无菌采集自全省6个地区15头野猪肝脏样本的分离菌株进行培养观察、革兰染色、生化鉴定、16S rRNA基因序列分析、药敏试验和小鼠致病性试验及病理组织切片,同时根据已报道的基因序列合成奇异变形杆菌的mrpA、rsbA、ureC、zapA、rsmA、hpmA、FIiL、ucaA、pm...