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水产养殖同微生态与微生物生态之间关系初探 总被引:24,自引:0,他引:24
水产养殖同微生态与微生物生态之间关系初探南京农业大学薛恒平薛彦青水中微生物的生态情况直接影响水产养殖业的发展,包括对鱼虾等的疾病防治及其生长发育的影响。近年,国内外在水产养殖中对水的生态环境,特别是微生物生态环境和水生动物(鱼虾等)体的微生物情况(微... 相似文献
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抗生素在养殖业中发挥了巨大的作用,其历史地位不可否认。但随着抗生素的大量使用及滥用,其弊端日益显露出来,诸如破坏动物体正常微生物群,导致微生态平衡失调;促进耐药菌株增加;增加易感生境的敏感性,促进机体的外源性感染和内源性感染;影响动物的免疫功能,使机体抗病减弱;抗生素等药物在畜产品 相似文献
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近年来我国水产养殖业的病害频发,养殖环境的日趋恶化,以及抗生素的滥用与诸多负面影响,严重困扰了我国水产养殖业的长足发展。而且人们对于安全水产品的呼声,也促进了许多安全高效添加剂的研制和应用。水产绿色饲料添加剂,能够促进水产动物生长,提高饵料利用率,增强免疫机能,降低死亡率等。因此,这些绿色饲料添加剂将越来越受行业的重视... 相似文献
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复合微生态制剂在水产养殖中的应用 总被引:5,自引:0,他引:5
随着水产养殖的迅猛发展和集约化经营程度的不断提高,渔业水域污染日趋严重,许多养殖池中有害藻类及病菌大量繁殖,水质条件不断恶化,已成为水生动物病害暴发的主要原因之一。另外,抗生素的滥用不仅损害水产动物的健康,而且产生了严重的耐药性。为了观察复合微生态制剂在水产动物上的使用效果,我们分别在甲鱼和对虾饲料中添加该制剂进行试验。 相似文献
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芽孢杆菌在水产养殖中的应用 总被引:13,自引:1,他引:13
近年来,随着水产养殖业的蓬勃发展,水产动物疾病频繁发生,大量使用和滥用抗生素形成的药物残留,影响人体健康。由于抗生素的种种弊端,在水产品生产中逐渐被禁止使用。这就要求开发新的无毒副作用,能防治疾病和进行营养调控的活菌制剂产品,芽抱杆菌微生态制剂应运而生。本文就芽抱杆菌微生态制剂在水产养殖中的应用作一阐述。1芽袍杆菌的种类及特点芽抱杆菌除了具有微生态制剂的优点外,还有自身的特点:1)稳定性好,不利的环境条件下能以抱子形式存在,具有耐高温(100℃)、耐酸碱、耐挤压和耐温度变化等特点,能够经受饲料加工中制粒… 相似文献
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黄树甫 《畜牧兽医科技信息》2018,(8)
正随着人们生活水平的提高,水生产品也成为我们饭桌上的常见食品,而水生动物疫病会对人类造成不可避免的伤害。我国的水产养殖业早就取得了很大的发展,但也存在着一些问题。其中最主要的是水生动物疫病防治。水生动物疫病不仅会使我国的水产养殖业的生产率下降,也会对人们的健康构成危害,尤其是那些水生动物与人类共患的疾病,如寄生虫病等。因此水产养殖业人员应该了解和分析水生动物疫病的特点,制定出相应的解决措施。 相似文献
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微生态制剂作为一类新型绿色环保的饲料添加剂,具有无毒、无害、无残留,且无污染等特点,在饲料中的应用为食品及饲料安全开辟了美好前景,使养殖中的治疗手段从抗生素主打的化学时代进入微观世界的新领域,益生素和益生元联合协同使用对动物肠道微生态平衡起到很好的调节作用,同时通过提高机体的体液免疫水平来增进机体的免疫防御机能,增强宿主对病原的非特异性免疫,并辅助免疫清除,调节宿主对潜在病原的免疫调节作用,减弱宿主对过敏原的过敏性反应。近年来,随着科技水平的提高,抗生素的副作用引起了人们极大的关注,抗生素滥用引起动物内源性感染或二重感染,导致耐药菌株的产生;长期使用可使饲养动物的细胞免疫、体液免疫功能下降,甚至导致动物发病或死亡。微生态制剂具有无毒副作用、无污染、无残留、不易产生抗药性和低成本等特点,且能明显改善畜禽消化道环境、增强机体免疫机能、提高饲料转化率,改善生长性能等,越来越受到人们的专注免疫,文中主要针对微生态制剂对动物免疫功能的作用机制做一简述。 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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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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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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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