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抗生素被禁用后,猪肠道健康问题是养猪业面临的一大难题.植物提取物是一种植物源添加剂成品,含有多种活性成分和营养成分,具有无毒副作用、低残留和不易产生耐药性等特点,是抗生素的理想替代品.文章对常见的植物提取物进行简要概述,重点综述不同种类植物提取物对猪肠道屏障和肠道微生物的影响,以期为今后合理使用植物提取物改善猪肠道健康... 相似文献
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文章总结了植物提取物的效果,可能的作用机理以及作为饲料添加剂在猪和家禽上的应用。植物源性饲料添加剂的种类很多,包括中草药、调味剂及其提取成分,主要是香精油。目前,还没有试验证实植物源性饲料添加剂可以提高饲料适口性。虽然大量的研究已经证明,植物源性饲料添加剂在体外具有很好的抗氧化和抗茵的效果,但是尚无动物试验证实。同时,植物提取物可以提高消化酶活性和动物的消化吸收能力也只是猜测。虽然只有少量的植物源性饲料添加剂与抗生素和有机酸对比性研究,但是却发现它们对胃肠道具有相似的效果,例如减少细菌菌落的数量、减少发酵产物(包括氨和胺类)、减少肠道相关淋巴系统的活动、提高盲肠前段肠道的吸收能力。这反映了这类饲料添加剂具有改善肠道功能的作用。此外,一些植物提取物似乎还可以促进肠道粘液的分泌,这可能是植物源性饲料添加剂能够提高畜禽生产性能的原因。研究表明,植物源性饲料添加剂可作为非抗生素类饲料添加剂在家畜上使用,例如有机酸和益生茵。但是,目前还没有其在猪和家禽上的使用效果及安全性的系统检测方法。 相似文献
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肠道菌群平衡与动物机体健康及生长发育密切相关,有机酸(organic acid, OA)作为一种绿色安全的功能性饲料添加剂,对动物具有抑菌、促消化、调节菌群平衡等作用。随着饲料产业的不断发展,OA已从饲料酸化、防腐、防霉逐渐向制剂化、动物生长促进剂和替抗产品转变,已成为畜牧行业广泛使用的一种功能性添加剂。笔者综述了猪肠道菌群的形成和分布,OA调节猪肠道菌群的组成结构和多样性及其对肠道菌群代谢产物产生和肠道免疫反应等方面的影响,并对其调控猪肠道菌群的作用机制进行探讨,旨在进一步揭示OA与肠道菌群的相互影响机制,为促进猪肠道健康与OA的合理利用提供借鉴。 相似文献
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姜黄素作为一种天然的多酚类植物提取物,具有抗炎、抗氧化、抗应激和改善动物肠道健康等多种生物学功能,已成为一种绿色安全高效的饲料添加剂。近年研究表明,姜黄素与肠道菌群存在紧密的相互作用。姜黄素能调控肠道菌群的组成和多样性,肠道菌群则影响姜黄素的转化。这种双向调控作用或许是姜黄素发挥生理功能的关键。此外,姜黄素被证实通过不同的机制抵抗多种病毒的感染,提示其具有成为新型抗病毒药物的潜力。因此,本文主要综述了姜黄素与肠道菌群之间的相互作用及姜黄素抵抗不同病毒感染的相关机制,以期为深入了解姜黄素对改善动物健康的作用机制和开发新型绿色饲料添加剂提供理论依据。 相似文献
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肠道微生物群有助于宿主肠道发挥多种生理功能,对改善猪的肠道健康、提高猪的生产性能具有重要作用。肠道微生物具有很强的可塑性,易受饮食、抗生素的摄入、病原体感染、宿主状况、外界环境等因素的影响。饮食的变化是影响肠道微生物群的主要因素。很多营养素和饲料添加剂具有调控猪肠道微生物的结构组成、促进肠道健康的作用。调节日粮营养素水平、补充饲料添加剂是猪生产中常用干预肠道微生物方法之一。文章综述膳食营养素和饲料添加剂(益生菌、益生元、酶制剂和植物生物素等)对猪肠道微生物群的影响,为其在猪生产中的应用提供参考。 相似文献
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丝兰属植物提取物是一种具有调节肠道微环境、减少动物氨气排放、促进细胞营养及提高动物免疫力等多种功效的功能性饲料添加剂产品。文章综述了丝兰属植物提取物的生理功能及其在养殖业中的应用效果。 相似文献
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外源核苷酸具有多种生物学功能,是一种无毒、无害、安全的新型功能饲料添加剂,在畜禽的生产性能提高方面发挥着重要作用,对动物胃肠道的发育、损伤修复、微生态区系平衡和肠道免疫产生很大的影响,本文就核苷酸对动物肠道的保护以及酵母核苷酸在猪生产中的应用给予了一定的阐述. 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