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粗脂肪含量是粮食、油料、饲料等产品标准中重要的质量指标,是评价产品品质的重要依据之一.国内外测定粗脂肪含量的方法有十多种,索氏抽提法是目前应用最广泛的测定方法,是公认的脂肪含量测定的经典方法.在实际工作中,此法存在的问题主要是抽提时间过长和抽提结束后抽提瓶不易恒重.围绕这些问题,我们对抽提过程和抽提前后采用的处理手段进行改进,改进以国标方法为参照,以热浸提-油重法和残余法为改进方法,对照比较了3种检测方法的测定结果. 相似文献
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索氏抽提法测定粗脂肪含量的改进 总被引：1，自引：0，他引：1
粗脂肪含量是粮食、油料、饲料等产品标准中重要的质量指标,是评价产品品质的重要依据之一。国内外测定粗脂肪含量的方法有十多种,索氏抽提法是目前应用最广泛的测定方法,是公认的脂肪含量测定的经典方法。在实际工作中,此法存在的问题主要是抽提时间过长和抽提结束后抽提瓶不易恒重。围绕这些问题,我们对抽提过程和抽提前后采用的处理手段进行改进,改进以国标方法为参照,以热浸提-油重法和残余法为改进方法,对照比较了3种检测方法的测定结果。1 改进方法原理经典索氏提取法测定脂肪是将样品放在抽提筒内以水浴蒸馏冷凝的乙醚进行回流浸提,… 相似文献
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以2种配合饲料和5种饲料原料作为实验材料，比较了采用国家标准（GB9433－94）测定饲料粗脂肪含量与采用改进法测定饲料粗脂肪含量的差异性。经F检验和t检验表明，两种测定方法的检测结果无显著性差异。可用改进法替代国标法来测定饲料中的粗脂肪含量。 相似文献
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粗脂肪含量测定影响因素 总被引：1，自引：0，他引：1
李谦世 《上海畜牧兽医通讯》1993,(2):22-22
我们在用国家标准GB6433-86测定饲料中粗脂肪含量时,遇到一些质疑,为了说明问题,作了一些比较实验。目前,我们在测定饲料中粗脂肪含量时,多采用索氏提取法。而市面上售出的索氏脂肪抽提器有回流式(用虹吸原理)和直滴式二种。按国标上讲,回流每小时达10次,但经实际观察达不到,每小时仅2次左右(注:做此比较实验时室温在29℃左右)。关于被测饲料的预烘时间,国标上有二种,一种是150℃烘2小时, 相似文献
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《黑龙江畜牧兽医》2018,(24)
为了比较索氏抽提残余法与ANKOM滤袋法测定饲料中粗脂肪含量的准确性与检测效率,试验从河北省和天津市的饲料加工厂采集12份饲料样品,采用索氏抽提残余法和ANKOM滤袋法同时对试验样品粗脂肪含量进行测定。结果表明:2种方法测定结果的相对偏差均在3%以下,符合《饲料中粗脂肪的测定》(GB/T 6433—2006)~([6])的要求;索氏抽提残余法和ANKOM滤袋法的差值在-0. 16～0. 32之间,比值在96. 57%～101. 94%之间,检测结果基本一致;经配对样本t检验,测定结果差异不显著(P0. 05)。说明二种方法均能准确检测出样品中粗脂肪含量,但索氏抽提残余法检测效率较低,而ANKOM滤袋法操作简易,检测效率较高,是值得推广的检测方法。 相似文献
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目前饲料粗脂肪的测定方法一般都依据国标ＧＢ６４３３－８６标准，以低沸点的乙醚作提取溶剂，借助索氏提取器，采用水浴加热，循环抽提试样中的油脂。该法操作较烦琐，抽提瓶大，烘干、称重不方便，乙醚沸点很低（３４．１５℃）易起火，乙醚蒸气有较强的刺激味，对人体有麻醉作用，特别是在夏天，很难将乙醚蒸气冷凝下来。为了克服上述弊端，笔者经多次试验，在国标法的基础上作了改进，用称量滤纸包代替称量抽提瓶，用电热套代替水浴锅，用沸程为６０～９０℃的石油醚代替乙醚，使测定时间缩短，测定方法简便，分析结果与国标ＧＢ６４３… 相似文献
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<正>国标GB6433—86测定饲料中粗脂肪的方法是比较经典的索氏脂肪提取法。但此法提取,抽提瓶大,烘干、称重不便,每次均要回收乙醚,费时费事,水浴锅必须是蒸馏水,才能保证抽提瓶称量准确。鉴于以上原因,本文在抽提脂肪基本步骤不变的前提下,作了小小的改进,取得满意效果。 相似文献
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目前饲料粗脂肪的测定方法一般都依据国标ＧＢ６４３３－８６标准，以低沸点的乙醚作提取溶剂，借助索氏提取器，采用水浴加热，循环抽提试样中的油脂。但该法操作比较麻烦，抽提瓶大、烘干、称重不方便。乙醚沸点很低（３４．１５℃），极易着火，乙醚蒸汽有较强的刺激味，对人体有麻醉作用。特别是在夏天，很难将乙醚蒸汽冷凝下来，既损耗大又对环境有严重影响。为了克服上述弊端，笔者经多次试验，在国标法的基础之上，作了几点改进，用沸程为（６０～９０℃）的石油醚代替乙醚，用电热套代替水锅，用称量纸包代替称量抽提瓶，使测定时间… 相似文献
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饲料中粗脂肪两种测定方法的比较探讨 总被引：1，自引：0，他引：1
粗脂肪是饲料中的一个重要组成部分,虽然各种动物对它的需要量不大,但是它在动物营养中起着很重要的作用。目前饲料中粗脂肪测定的国标方法GB／T6433—2006中提及有直接索氏抽提法和盐酸水解法,为了验证这两种方法检测结果之间的差异性,本文通过运用这两种方法分析多种饲料原料的粗脂肪含量,对这两种方法的特点进行比较探讨,得出盐酸水解法是适用有效的方法,其检测结果能更真实的反映饲料中的粗脂肪含量,对于饲料配方设计和降低饲料成本具有非常重要的指导意义。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
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。 相似文献
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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。 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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Billinghurst RC Brama PA van Weeren PR Knowlton MS McIlwraith CW 《American journal of veterinary research》2004,65(2):143-150
OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis. 相似文献