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瘤胃真胃是瘤胃微生物区系中的一种功能菌,其在反刍动物瘤胃内纤维物质消化过程中发挥了重要作用,并参与瘤胃内淀粉及蛋白质的降解过程。本文在目前已有的研究基础上,综述了瘤胃真菌在饲料降解中的作用及对真菌种群影响的因素,并简要地概括了此领域尚待解决的问题,以备进一步研究和探讨。 相似文献
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瘤胃真菌在纤维降解中的作用 总被引：2，自引：0，他引：2
瘤胃真菌是瘤胃微生物区系中的一种功能菌，其在反刍动物瘤胃内纤维物质消化过程中发挥了重要作用，本文在目前已有的研究基础上，综述了瘤胃真菌在饲料降解中的作用及对真菌种群影响的因素，并简要地概括了此领域尚待解决的问题，以备进一步研究和探讨。 相似文献
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在过去 1 0年中 ,对反刍动物消化过程中起主要作用的瘤胃微生物区系研究取得了很大进展 ,但主要集中在瘤胃细菌及纤毛虫的数量、分布及作用等方面 ,而对瘤胃真菌研究较少。研究表明 ,瘤胃真菌可分泌一系列降解植物纤维及细胞壁的高活性复合酶 ,对饲料特别是大颗粒、大片段植物纤维有很强的降解能力 ,启示人们注意到瘤胃真菌在新型饲料开发上有潜力。本文就瘤胃真菌在饲料降解中的作用及其在未来饲料工业中的应用前景作一综述。1 瘤胃真菌的特点在Ｏｒｐｉｎ于 1 975年首次发现绵羊瘤胃厌氧真菌以前 ,瘤胃微生物被认为由细菌和纤毛虫构成。… 相似文献
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反刍动物瘤胃真菌的研究进展 总被引：6，自引：0，他引：6
瘤胃真菌是瘤胃微生物区系中一人种功能菌,有着自身的分类学位置和生活周期,在反刍动物瘤胃内纤维物质消化过程中发挥重要作用,并参与瘤胃内淀粉及蛋白质的降解过程,本文综述了瘤胃真菌的分类学位置、生活周期、在饲料降解中的作用及此领域沿待解决的问题。 相似文献
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反刍动物瘤胃真菌的作用与研究进展 总被引：1，自引：0，他引：1
目前在反刍动物瘤胃中已经发现有200多种微生物,其中约有30多种占有主导作用。但是,过去对反刍动物瘤胃微生物区系的研究主要集中在瘤胃细菌及纤毛虫的数量、分布及其生理活动和作用等方面。直到1977年Orpin等人首次报道从绵羊瘤胃中分离出厌氧真菌,并对其进行了描述,同时阐述了对植物细胞壁的降解作用后,人们才开始转向瘤胃真菌的研究。目前人们对瘤胃的原虫和真菌还知之甚少。近期有研究表明,瘤胃真菌在降解饲料,特别是大颗粒、大片段、植物纤维过程中起着重要作用,以及发现瘤胃中的真菌还具有降解蛋白质和淀粉的能力。 相似文献
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反刍动物消化生理的最大特点是瘤胃微生物能进行复杂的消化代谢。为了提高粗饲料的利用率,人们对反刍动物胃肠道消化功能起主导作用的微生物区系进行了大量的研究,但主要集中在细菌和纤毛虫上,对瘤胃真菌的描述却很少。近年来人们开始转向瘤胃真菌的研究。得知,瘤胃真菌在降解饲料,特别是大颗粒、大片段植物纤维过程中起着重要作用。本文就瘤胃真菌的特点、形态、在饲料降解中的作用及其应用前景做一综述。1瘤胃真菌的特点真菌普遍存在于许多草食动物(如反刍动物、马、袋鼠和象)的消化道中,目前从瘤胃中分离得到的真菌共计5个属十余个种之多… 相似文献
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瘤胃细菌和真菌均具有很强的粗饲料降解能力,但二者对粗饲料的附着和降解机制存在一定的差异,且二者之间存在着复杂的协同和竞争关系。本文综述了瘤胃真菌和细菌对粗饲料的附着、降解及在粗饲料降解过程中的互作。 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