共查询到20条相似文献，搜索用时 188 毫秒
1.
在集约饲养的鸡群,大肠杆菌病的危害非常严重,有关雏鸡和肉仔鸡感染大肠杆菌病导致严重损失的报道增多,但产蛋肉种鸡感染造成急性死亡的病例少见报道。1993年3月我地区某种鸡场发生了一起以卵黄性腹膜炎为特征的大肠杆菌病,现将诊断过程报告如下。 1 发病情况及临床表现发病鸡群为38周龄平面饲养的3152羽AA肉种鸡,产蛋水平偏低。全群产蛋率65.2％。3月9日,鸡群死亡数骤增,持续5天,日死亡9～14羽,其中绝大多数为产蛋母鸡,公鸡亦有零星死亡。产蛋率下降5.12％。大群鸡情种状态尚好,饮食欲略有下降。鸡群中很少见到病鸡。偶见企鹅 相似文献
2.
<正>1细菌性疾病1.1鸡大肠杆菌病(Avian colibacillosis,E.Coli)治宜消除病原,重在提前预防。(1)建立健全生物安全体系,做好免疫接种。肉鸡7～10日龄,蛋鸡75～80日龄,颈皮注射禽大肠杆菌多价油苗。(2)雏鸡净化。根据种鸡用药史和药敏试验结果,选用作用于禽垂直传染性疾病如禽大肠杆菌病、鸡白痢、禽亚利桑那病、禽支原体感染等的 相似文献
3.
对确认鸡马立克病的肉种鸡群采取检测死淘鸡，整顿鸡群，注射克马灵药，及早免疫等综合防治措施，综合治理后种鸡产生水平恢复接近健康鸡，病种鸡恢复后育雏试验表明，２４周龄成活率达９２％以上，没有发生马立克氏病。 相似文献
4.
鸡慢性呼吸道病 (ＣＲＤ)是由鸡毒霉形体 (ＭＧ)引起的 ,其特征为呼吸罗音、咳嗽、鼻漏。种鸡可通过蛋黄将ＭＧ垂直传给其后代 ,使后代发病 ,并保持较低的产蛋率水平。我们通过给ＭＧ高阳性种鸡群连续三次注射ＭＧ灭活油苗 ( 3 5日龄、80日龄、1 3 0日龄 ) ,使其后代成为无ＭＧ健康鸡群。1 材料与方法1 .1 鸡毒霉形体全血平板凝集抗原和ＭＧ灭活油苗均由哈兽所提供。1 .2 高ＭＧ阳性种鸡群 :以ＭＧ全血平板凝集抗原 ,检测 3 2日龄的蛋用种鸡群 ,抽检数占全群的 1 0 %。种鸡群Ａ的ＭＧ阳性率为 2 3 .5%,种鸡群Ｂ的ＭＧ阳性率为 1 7.4 %,… 相似文献
5.
6.
7.
大肠杆菌病在产蛋鸡群一旦发生，往往不易控制，死亡绵延不断．产蛋性能下降．造成相当大的经济损失。由于大肠杆菌对许多抗菌药物产生抗药性，给临诊选药带来困难，许多药物不能控制大肠杆菌病，从而延误治疗时机，使病情反复。我们门诊部经过一年多的临诊试验，通过应用病死鸡的内脏组织进行细菌分离，并做药敏试验，选出敏感药物，指导冶疗大肠杆菌病，取得令人满意的效果。 相似文献
8.
1998年4月，笔者对某鸡场种鸡因注射大肠杆菌油性剂灭活菌菌引起的不良反应进行了观察及处理，现报道如下。一、注射经过、发病情况和症状某鸡场采用纵向机械式通风、网上平养方式饲养海赛克斯褐父母代种鸡2300只。根据以往鸡群大肠杆菌病发病较为普遍的情况，故本批种鸡在110日龄时选用某所生物制品研究室生产的鸡大肠杆菌多价油性剂灭活菌苗，按使用说明在大腿部肌肉注射，剂量为0．5毫升／只。注射菌苗后第3天，个别鸡出现精神沉郁，食欲降低或不食。第4天，引起反应鸡数逐渐增多，近40％母鸡同时出现缩颈闭眼，被毛松乱，蹲伏懒动，采食… 相似文献
9.
10.
刘庆功 《畜牧兽医科技信息》2012,(2):97
对产蛋鸡注射疫苗直观的反应是引起产蛋下降。在实际生产过程中,部分养殖户由于没有按照正确的油苗操作使用方法,抓鸡动作过于粗暴,注射疫苗所选择的时间不当等诸多原因,在注苗以后产生了较为严重的应激反应,引起生产鸡群产蛋下降,有的甚至死亡,直接影响了经济效益。笔者在实际工作中总结出在产蛋鸡进行免疫时,既能降低免疫反应又能提高免疫效果的小 相似文献
11.
12.
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
13.
14.
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
15.
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
16.
乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制. 相似文献
17.
18.
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
19.
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