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鸡球虫病是一种重要的鸡寄生虫病,长期以来药物防治成为抗球虫病的主要手段,但由于药物的残留和耐药性等问题,使得鸡球虫病的免疫学研究受到广泛关注。本文对柔嫩艾美耳球虫不同发育阶段重要的免疫保护性抗原研究进行了综述,旨在为鸡球虫病的免疫防治提供新思路和参考。 相似文献
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鸡球虫种类很多,目前世界公认的有8 种,其中危害最大的有艾美耳属的柔嫩艾美耳球虫、毒害艾美耳球虫2种,是养鸡业中严重多发,且防制困难的疾病之一,其死亡率达40%~50%。近几年来由于各养殖户缺乏疾病防制知识,使用药物防治球虫病时并不能做到合理选用和科学应用,导致球虫的耐药性不断增加,球虫病在一定区域仍然广泛流行。作者阐述了如何合理应用抗球虫药物来减少药物产生耐药性,使其更有效地治疗鸡球虫病。 相似文献
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球虫病(Coccidiosis)是由艾美耳属(Eimeria)的单细胞寄生原虫引起的严重危害养禽业发展的重要疾病之一,遍及世界各地,其中柔嫩艾美耳球虫(E.tenella)是最常见的病原.据报道(1992),全世界每年由鸡球虫病造成的经济损失高达20亿美元.但药物防治和球虫活苗的使用又存在诸多问题,迫使人们寻找新的免疫预防方法.本研究应用DNA重组技术克隆了λMzp5-7基因,同时构建原核和真核表达载体并表达,利用原核表达的融合蛋白和真核重组质粒免疫动物,观察不同的免疫策略诱导的免疫反应,为球虫病的防治研究奠定基础. 相似文献
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我国鸡球虫病防治研究的概况 总被引:15,自引:0,他引:15
曾明华 《中国兽医寄生虫病》1997,5(1):49-51
鸡球虫病是一种危害性很大的原虫病。主要是由艾美耳属9种球虫所致,其中最重要的有6种,即柔嫩艾美耳球虫、毒害艾美耳球虫、堆型艾美耳球虫、布氏艾美耳球虫、巨型艾美耳球虫和变位艾美耳球虫。据统计,本病每年给美国养鸡业造成2亿美元的损失。在英国,据保守的估计,养鸡业每年至少要花费550万英磅用于防治鸡球虫病。据北京农业大学调查,鸡球虫病遍布全国各地,其发病率高者可达100%。随着集约化养鸡的发展,本病的危害将日趋严重。因此,如何防治本病是目前养鸡业的重要课题之一。多年来,我国的科学工作者为了防治鸡球虫病进行了大… 相似文献
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杨恒东 《上海畜牧兽医通讯》1995,(4):26-27
球虫病是养禽业中最常见的疾病之一,常给养禽业带来不必要的经济损失。由于不同球虫株攻击家禽方式不同,导致临床症状变化不一。球虫病又很容易被忽略,那么采取什么措施来防制呢? 一、球虫病的病原体及临床症状 鸡球虫病是由顶器亚门艾美耳属的一种单细胞寄生虫引起的,它们在肠道上皮增殖,虫体很小。现在已经知道,艾美耳球虫具有动物特异性,只能感染鸡,在小鸡体中已检测到9种艾美耳球虫,其中5种证实为致病性的,它们是:堆形艾美耳球虫,巨型艾美耳球虫,毒害艾美耳球虫、柔嫩艾美耳球虫和布氏艾美耳球虫。球虫病的爆发从轻度到重度感染状况不一。球虫有种的差异,但它们引起的普遍的临床症状:有血便,死亡率高,精神萎靡,食欲下降,消瘦,腹泻,蛋鸡产蛋下降,病鸡蜷缩而立,眼半睁半闭,羽毛脏乱,翅膀下 相似文献
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中药"球康"微粉制剂对鸡柔嫩艾美尔球虫病的防治试验 总被引:2,自引:0,他引:2
鸡球虫病是养鸡业中危害最严重的疾病之一。目前,对该病的防制主要有疫苗的免疫接种和药物防治两种方法。前者因有不少关键环节尚待解决且疫苗预防风险。陀较高,在我国难以广泛应用。因此,药物防治仍是当前控制球虫病的主要手段。化学药物防治球虫病易产生抗药虫株和有害残留等,中草药因其毒副作用小、不易产生耐药性和残留越来越受人们的重视。本课题组经多次试验,筛选出抗球虫效果良好的中药复方制剂“球康”。为了探求“球康”的给药日龄和给药剂量,进行人工感染鸡柔嫩艾美耳球虫的防治试验,现将试验结果报道如下。 相似文献
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NP-AC-1中草药添加剂抗鸡E.acervulina和E.necatrix效力试验 总被引:2,自引:0,他引:2
鸡球虫病是一种危害极其严重的全球性寄生虫病,全世界每年因球虫病造成的经济损失约20多亿美元.长期使用化合药预防所产生的耐药性、药物毒副作用和高残留已经引起了社会各界极大关注.中草药饲料添加剂具有促进家禽生长、提高机体免疫力等多种生物学效应,并因其低毒、无害、无残留、不易产生耐药性等独特优势愈来愈被我国畜牧工作者重视.鸡球虫病是由艾美耳属(Eimeria)球虫引起,其中柔嫩艾美耳(E.tenella)的致病性最为严重,本课题组开发的中草药饲料添加剂(主要由青蒿、仙鹤草等等组成)在临床试验中对E.tenella所引起的鸡球虫病有良好的预防效果.本试验观察了该添加剂对堆型艾美耳球虫(E.acervulina)、毒害艾美耳球虫(E.necatrix)的疗效,为临床用药提供更为科学依据. 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