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精氨族氨基酸在调控机体营养代谢和免疫反应方面的重要作用是近年来猪营养领域一个重大的发现,其机理和效果非常明确,国内外学者对此进行了诸多综述。但由于精氨酸成本相对过高,如果在饲粮中按有效剂量添加时会对其他氨基酸代谢产生干扰且占用配方空间,于是业内人士希望通过另一种物即N-氨甲酰谷氨酸（NCG）来提高机体精氨酸含量进而改善动物健康状况和生产性能。 相似文献
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精氨酸是动物机体代谢的重要氨基酸,是新生哺乳动物的必需氨基酸,正常情况下成年哺乳动物能够合成满足机体自身需要的精氨酸,但在受伤、肠道受损等应激状态或病态下合成精氨酸的量不能满足机体的需要量,所以精氨酸是成年哺乳动物的条件性氨基酸。由于家禽体内缺乏甲酰磷酸酶等关键酶,不能合成精氨酸,只能由日粮提供,所以精氨酸是家禽的必需氨基酸。精氨酸在动物营养代谢中发挥着重要的作用,同时在畜禽生产中也存在着广泛的应用。本文对精氨酸的主要生理作用及其在畜禽生产中的研究与应用进行综述。 相似文献
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代谢是一切生理活动的基石,氨基酸代谢作为三大物质代谢之一,参与机体的多种生理活动,与宿主免疫细胞的功能有密切关系,在疾病的发展中具有不可替代的作用。为探究乳房链球菌(Streptococcus uberis,S.uberis)感染对乳腺上皮细胞中氨基酸代谢的影响,本研究以S.uberis和乳腺上皮细胞系(EpH4-Ev)为研究对象,采用靶向氨基酸代谢组学技术对细胞中的氨基酸进行定量分析,并采用RT-qPCR和Western blot方法对关键氨基酸——精氨酸代谢通路关键酶进行验证。结果表明：S.uberis感染细胞后,细胞中甘氨酸、苏氨酸、鸟氨酸、天冬酰胺和谷氨酰胺的含量被显著上调(P<0.05),谷氨酸、脯氨酸、精氨酸、丝氨酸、组氨酸、缬氨酸、异亮氨酸、丙氨酸、酪氨酸、色氨酸、赖氨酸和天冬氨酸的含量被显著下调(P<0.05),其中,精氨酸含量变化极显著(P<0.000 1,VIP>1.2),天冬酰胺和谷氨酰胺两种生糖氨基酸显著上升(P<0.05),赖氨酸和亮氨酸两种生酮氨基酸含量显著下降(P<0.05)。进一步研究精氨酸分解代谢通路发现：S.ube... 相似文献
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精氨酸是目前发现的动物细胞内功能最多的氨基酸,几乎哺乳动物机体中所有组织均利用L-Arg合成细胞浆蛋白和核蛋白,L-Arg在细胞分裂、伤口复原、蛋白质合成和分泌激素等生理过程起着重要的作用。精氨酸作为必需氨基酸,在怀孕母猪和幼龄仔猪及猪在病理状况下,内源合成不能满足其需要。根据传统的营养标准(NRC1998)配制的日粮,精氨酸不能满足猪的需求,额外添加精氨酸可提高猪的生产性能。由于精氨酸与赖氨酸、色氨酸、组氨酸的吸收存在拮抗效应及价格昂贵,限制了精氨酸的使用。精氨酸生素可激活从谷氨酰胺和脯氨酸生成精氨酸的生化过程,促进精氨酸的内源生成。日粮添加精氨酸或者精氨酸生素,均有助于提高妊娠母猪的产活仔数及出生窝重、提高哺乳仔猪的增重及减少断奶应激。文中就精氨酸的代谢、调控及精氨酸和精氨酸生素在猪营养中的应用,特别是精氨酸与胚胎发育、新生动物蛋白合成和生长、仔猪肠道健康和疾病感染调控等方面的研究成果作一综述。 相似文献
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肠道细菌在营养素代谢过程中起重要作用,进而影响机体整体代谢。小肠是氨基酸代谢的重要场所,对宿主蛋白质营养与肠道健康至关重要。然而,大量进入小肠的氨基酸在首过肠道代谢中被细菌转化代谢和利用。此外,小肠细菌对氨基酸的代谢呈现出区室化特征,这不仅表现在不同肠段上,还体现在层面上的差异。细菌对氨基酸的代谢产物包括二肽、多胺,它们能影响宿主肠道健康,细菌分解尿素再合成氨基酸的功能可能在一定程度上缓解宿主对氨基酸的需求。本文主要综述了小肠细菌在氨基酸首过肠道代谢中的作用与去路、对氨基酸代谢的区室化以及氨基酸代谢产物对宿主的影响。 相似文献
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脂质代谢不仅影响人类健康,对畜禽生产也至关重要,研究脂质代谢的营养调控策略有重要意义。作者主要介绍了蛋氨酸（Met）、亮氨酸（Leu）、精氨酸（Arg）和谷氨酸（Glu）这4种对脂质代谢调控作用显著的氨基酸。从生理水平、细胞水平和分子水平上总结了4种氨基酸对哺乳动物脂质代谢的调控及其作用机理,并从4种氨基酸在营养学研究中的作用、在动物试验中的生理效应、对脂质代谢调控的作用机理及各种氨基酸的组合效应等方面进行综述,重点综述了氨基酸对脂肪、肝脏和肌肉组织脂质代谢的调控及其作用机理。同时回顾了4种氨基酸在基础研究与畜牧生产应用上取得的进展,进一步分析了未来研究氨基酸对脂质代谢调控深层机理的可能方向,以期为氨基酸的精准利用提供参考。 相似文献
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功能性氯基酸——精氦酸（Arg）具有重要的生理、代谢和营养作用,几乎机体中所有组织均利用Arg合成胞浆蛋白和核蛋白,精氨酸在促进肌肉蛋白质合成、增强机体的免疫力、细胞分裂、伤口复尿和激素分泌等各种生理过程中,也都有着重要的角色。Arg为条件性必需氨基酸,在应激状态下和特殊生长阶段,为必需氨基酸,仔猪体内合成的精氨酸不能满足生理代谢需要。但是精氨酸的吸收与赖氨酸等桔抗,因此,对精氨酸及其内源性合成调控研究具有极大的应用价值和实践意义。精氨酸生素（Arginineactivatoradditive,AAA）是N-乙酰谷氨酸（N-acetylglutamate,NAG）的类似物,作为一种新型的功能性氨基酸,可以有效调控内源性精氨酸合成,进而促进动物生长性能。本文就精氨酸和精氨酸生素特别是其对机体内源性精氨酸合成调控及其在仔猪和母猪中的研究进展与应用作一综述。 相似文献
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氨基酸不仅是蛋白质和其他含氮化合物合成的重要前体,还参与体内主要代谢途径的调控。当氨基酸不足时,机体内多种机制参与调节体内平衡,包括快速停止蛋白质合成、增加氨基酸合成和转运,以及加强自噬作用。越来越多的学者证明氨基酸可作为信号分子参与细胞内信号传导过程,可以调节其他营养素如脂肪和能量的代谢,最终导致机体整体代谢的改变。本文主要综述细胞内氨基酸的营养感知与应答机制,涉及氨基酸应答(AAR)和雷帕霉素靶蛋白(TOR)2条信号转导通路,并探讨这2条信号通路对下游营养素代谢途径的调节。 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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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。 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