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因运输应激引起的各类疾病是困扰肉牛养殖业发展的难题,不少牧场肉牛运输入场后的发病及死亡率较高,增重水平低,严重影响生产经济效益的发挥。运输应激综合征的发生通常是由多种不良因素综合作用的结果。应激会干扰动物正常生理机能,降低牛只免疫力,常会引发支原体为主继发大肠杆菌等病原微生物感染,导致呼吸道、消化道甚至全身病理性反应。病牛由于营养摄入不足而机体脂肪蛋白消耗增加导致极度消瘦。犊牛的生理和免疫系统尚未发育完善,因此对应激因素尤为敏感。本文对犊牛运输应激相关研究进行分析和阐述,包括运输相关应激因素,以及评估运输应激的指标和方法,以期降低运输应激导致的不良影响,改善运输犊牛的健康和福利。 相似文献
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蛋鸡在热应激条件下的营养调控 总被引：1，自引：0，他引：1
本文主要综述了蛋鸡在热应激条件下，从饲粮和添加剂两方面进行营养调控的措施和方法。热应激降低家禽的生产性能，导致体内许多生物化学和生理性能的改变。持续热应激可导致鸡热衰竭而死亡，通过选择性饲喂和（或）饲喂高脂肪日粮、添加抗热应激添加剂可使这些生理变化得以改变。 相似文献
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应激是动物机体在多种环境、生理和心理等因素的刺激下，出现的生理与心理等全身性的非特异性的适应性反应。随着我国生猪养殖业规模化和集约化程度的提高，养猪生产者都追求以有限的养殖空间来生产更多的猪只，这导致了养殖密度的增加、猪群应激发生的概率不断上升。应激导致的危害日益突出，成为了阻碍猪只健康生长的重要的因素之一。本文回顾了应激的病理学概念、应激的种类与危害、抗应激的营养支持理论；针对应激问题的解决，本文提出了对猪群添加功能性的维生素和氨基酸来的方法，并介绍了该方法在猪场实际应用的案例。 相似文献
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断奶应激主要由营养应激、心理应激、环境应激、疫病应激等叠加而成，对断奶仔猪的影响尤为严重，可以说是猪一生中最大的应激。猪场如果对这些应激处理不当，会严重影响猪只后期的生长性能甚至导致疾病的高发。文章讨论了断奶应激给仔猪带来的影响，特别是断奶后仔猪在消化道发育和母源抗体等方面的适应性变化，同时就缓解断奶时的几种应激提出了相应的解决方法。 相似文献
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内质网是蛋白质和脂质生物合成以及跨膜蛋白折叠的场所。生理和病理情况都可影响内质网的功能，导致内质网应激。长期和严重内质网应激可导致细胞的自噬和/或诱导细胞凋亡。多项研究表明，内质网应激是导致许多疾病的主要因素。因此，对内质网应激通路的调节已成为一个潜在的治疗靶点。槲皮素是属于黄酮类植物衍生的次生代谢物，具有一系列有益作用。近年来的研究发现，槲皮素可通过调控内质网应激信号，降低机体发生癌症、肝脏和胰腺疾病、心血管疾病、肠道疾病的风险，减少器官/组织损伤，进而维持动物机体健康。本文主要综述槲皮素调节动物内质网应激中的作用机制及研究进展，旨在为槲皮素的进一步开发利用和治疗动物内质网应激相关疾病方面提供参考。 相似文献
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热应激是影响畜禽生产的重要因素之一，可导致畜禽采食量减少，生长速度下降，免疫机能抑制，发病率增高：同时还导致肌肉系水力下降，寿命缩短等诸多问题。我国畜牧生产主要基地大部分位于暖温带和亚热带，夏季日平均气温普遍高于27．5℃（中国统计年鉴，2006）。热应激引起的疾病和畜禽生长缓慢造成了巨大的经济损失，已引起国内外畜牧工作者的广泛关注。随着对热应激产生机理和热应激蛋白的深入研究，人们进行了大量抗热应激添加剂的试验研究。人们根据畜禽在热应激时的表现及血液生化指标的变化对症下药，筛选出一些具有抗热应激作用的解热镇静剂、电解质、维生素、抗生素以及一些微量元素。 相似文献
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１、群体应激。将母猪与乳猪分开，对母猪来说是一个很大的应激，原因是由将乳猪移至新圈和将不同的小猪混养在一起，这些应激足以导致乳猪容易患病，为此在离乳前几天就混养，有助于减少离乳的应激和离乳后猪只打架的发生率。 ２、营养应激。把液体奶料突然改变为固体饲料，是一个应激。从有规律的每天１６－２４小时吸吮母乳，突然变为采食固体饲料，常发生乳猪拒绝进食的现象。而后在饿了１２－１５小时后，乳猪会饱餐一顿，这时所摄入的固体饲料数量，使正在发育的消化系统负担过重，容易导致仔猪腹泻。 ３、离乳应激。离乳后乳猪的生长… 相似文献
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应激的动物比正常动物更容易发病，在生猪市场低迷的情况下，降低养猪应激就显得更为重要。生产中应激因素很多，可以导致猪只疾病的发生。在炎热的夏季，热应激会导致猪的生产性能急剧下降，甚至造成死亡；在秋冬季节，应激对猪呼吸道疾病的影响更为严重。其它如饮水短缺、饥饿、防疫、转群、运输、拥挤、微生物的入侵等等都会造成应激。 相似文献
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一、生产实际中的免疫应激现象
母猪刚产后、仔猪断奶时，饲养条件较差时，猪只生病时，反复多次免疫接种的猪场，均会出现采食量降低、饲料利用率下降和生长迟缓。但在运用类固醇激素，饲料添加抗生素，断奶猪饲料添加抗应激剂健力源等却能促进猪只的生长。这两种现象都与免疫应激有关，前者是导致了免疫应激，后者是减轻和规避了免疫应激。 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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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