不同底物对植酸酶酶活检测的影响

试验采用2×5完全随机试验设计,考察不同底物(P3168和P8810)对不同酶活水平(6000、8000、10000、12000和16000U/g)的植酸酶酶活检测的影响。结果表明,以P8810为底物检测的植酸酶酶活显著高于使用P3168为底物的检测结果,但底物类型与酶活水平之间没有显著的互作效应。使用P8810与使用P3168的检测结果之间存在显著的线性关系(P=0.00),线性方程为:y(P3168)=0.843x(P8810)-431.16,R2=0.987。通过对曲线预测值验证的结果表明,可以使用P8810替代P3168作为底物进行植酸酶酶活检测。     

饲用植酸酶酶活测定过程中底物的影响研究

参照国标法测定饲用植酸酶活性,研究不同来源的底物植酸钠、底物浓度、底物pH对饲用植酸酶活性的影响。结果表明,以P8810为代表的植酸钠盐水合物作为底物,其测定出的植酸酶酶活显著高于使用以P3168为代表的植酸钠作为底物所测定的植酸酶酶活。以P8810作为底物时,其反应浓度在高于6.6 mmol/L时,会产生底物抑制效应。以P8810作为底物时,调节底物pH至国标中定义的5.5与未调节pH所测得的植酸酶酶活相比较,差异并不显著,且在低底物pH条件下,某些植酸酶同样能够释放出最大催化活性。因此现有的国标法测定饲用植酸酶活性已与实际应用有一定的差别,不能照搬国标方法测定现有饲用植酸酶产品。     

植酸酶的特性及稳定性效果的对比研究

试验就植酸酶的相关特性及其在此基础上的应用选择功效进行研究,并对市场上占有率较高的三个国产知名企业生产的植酸酶产品(P1、P2、P3)进行稳定性研究,比较这三种植酸酶产品在不同pH值、不同温度下(室温、80℃水浴、90℃常湿)和不同储存时间的酶活,为生产实践中合理选择使用植酸酶提供参考依据。结果表明,P2在酶活高峰pH值4.5～5.0表现出的酶活显著高于P1和P3(P0.05)。高温稳定性效果P3显著优于P1和P2(P0.05)。     

植酸酶磷当量的研究

<正>1植酸酶活性与磷当量之间的关系酶活指酶催化其底物能力的大小,通常用活力单位来表示。目前国际上通用的植酸酶酶活定义为37℃及pH值5.5的条件下,1min内从5.1mmol/l的植酸钠溶液中水解1μmol无机磷所需要的酶量为一个酶活单位。所谓当量关系就是不同物质之间针对某一共     

马铃薯渣作培养代料的两种侧耳属食用菌菌糠中两种饲用酶活性的检测研究

本研究以培养代料含马铃薯渣的凤尾菇菌糠、小白侧耳菌糠为研究对象,检测其中植酸酶及β-葡聚糖酶的酶活。凤尾菇菌糠植酸酶酶活在pH2.5下为0.0822U/g,在pH5.2下为0.0786U/g。小白侧耳菌糠植酸酶酶活在pH2.5下为0.1052U/g,在pH5.2下为0.1027U/g。凤尾菇菌糠β-葡聚糖酶酶活0.0260U/g,侧耳β-葡聚糖酶酶活为0.0354U/g。结果表明,加入马铃薯渣做培养代料的凤尾菇、小白侧耳菌糠具有一定的饲用酶活性,用其作禽畜饲料加工时,可适量减少饲用酶的加入量,以节约成本。     

白酒酒糟制备多酶益生菌饲料发酵工艺研究

选择产甘露聚糖酶枯草芽孢杆菌L-1、产植酸酶枯草芽孢杆菌L-2、产木聚糖酶YB-5、乳酸片球菌Rp作为制备多酶益生菌饲料的生产菌种。通过单因素和正交试验最终确定最佳底物干基组分为36%白酒酒糟、26%玉米粉、28%麸皮、8%豆粕,料水比10.8,装填量20 g/250 ml。结果表明:多酶益生菌饲料中益生菌活菌数为(1.97±0.09)×10~(11)cfu/g,甘露聚糖酶酶活(11.62±0.26)U/g、木聚糖酶酶活(15.30±0.36)U/g、植酸酶酶活(16.37±0.16)U/g、蛋白酶酶活(15.27±0.16)U/g以及淀粉酶酶活(19.37±0.33)U/g。     

生长猪植酸酶的磷当量研究

本文旨在研究饲粮中添加植酸酶对植酸磷利用的影响,确定生长猪的植酸酶磷当量。本试验采用单因素试验设计,以NaH2PO4.2H2O提供外源无机磷,同时添加植酸酶,设计1个低磷基础日粮、4个加磷日粮和3个加酶日粮,分别提供0.4、0.8、1.2、1.6g/kg的有效磷或500、750、1000FTU/kg植酸酶。选择96头体重22kg左右的杜长大三元杂交猪,随机等分到8个处理中。通过回归分析,建立响应指标(猪趾骨折断强度和趾骨灰分磷含量)与外源磷添加量之间的线性关系,进而确定植酸酶的磷当量值。结果表明:(1)随外源磷和植酸酶水平的提高,试验猪生产性能明显改善(P<0.05),趾骨灰分磷含量和血磷水平都极显著地升高(P<0.01);(2)无机磷添加水平与响应指标之间存在较强线性关系:y=10.79x 27.23(x-添加磷(g/kg),y-趾骨强度(kg),R2=0.92);y=1.44x 6.86(x-添加磷(g/kg),y-灰分磷(%),R2=0.99);(3)植酸酶的磷当量值与日粮中植酸酶和无机磷水平密切相关,同时也受相应指标种类的影响。本试验条件下,500、750、1000FTU/kg植酸酶分别可替代1kg玉米-豆粕日粮中0.09g、0.44g和0.72g(折断强度)或0.23g、0.58g、1.06g(灰分磷)无机磷。     

国标法测定植酸酶活性存在问题的探讨

利用国标法测定植酸酶活性过程中发现,植酸钠底物溶液pH为6.48,高于酶活性单位定义中pH5.5。为进一步探讨植酸钠底物溶液pH对植酸酶活性的影响,本试验研究了调节与不调节植酸钠底物溶液pH对样品空白的吸光值以及植酸酶活性的影响。结果表明:将植酸钠溶液pH由6.48调至5.5对酶活测定中的样品空白无显著影响(P>0.05),但极显著影响植酸酶活性(P<0.01),未调节pH组植酸酶活性仅相当于调节pH组的66%,利用不同的酸调节植酸钠溶液pH,对植酸酶活性无显著影响(P>0.05)。     

无淀粉麦麸为底物体外植酸酶活性评价方法的建立

为提高体外检测方法的科学性和客观性,预测植酸酶在动物体内的活性和作用效果,研究以无淀粉麦麸为底物,探索并建立了一种更为客观评价植酸酶活性的检测方法.与现有的植酸酶酶活测定国家标准相比,在不同pH值的缓冲液中检验植酸酶降解天然植酸的效果,具有更为科学、客观与简便等优点.     

水浴法测定饲用植酸酶耐热性方法的研究

试验研究不同条件对植酸酶水浴耐热性的影响。分别稀释4种植酸酶酶活力40、20、10、2 U/mL,测定80℃和85℃水浴5 min的耐热性。结果表明,稳定性强的植酸酶受酶浓度的影响较小,稳定性较差的植酸酶受影响较大,当处理液酶活力低时,耐热性结果较高。取3种植酸酶样品,分别使用缓冲液Ⅰ、缓冲液Ⅱ、水为耐温稀释缓冲液,测定85℃水浴5 min耐热性,结果表明:缓冲液Ⅰ作为稀释缓冲液测定的耐热性结果最高,其次是缓冲液Ⅱ,水作为稀释缓冲液时测定的耐热性结果最低。取3种植酸酶样品,分别在pH值5.5和5.0缓冲体系中测定85℃水浴5 min耐热性,结果表明,植酸酶在与最适pH值相近的条件下进行耐热性处理,测定的耐热性结果相对较高。研究表明,本试验的3种条件对水浴法测定植酸酶耐热性的结果均有影响,制定检测标准时需要明确测定条件。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.