共查询到20条相似文献,搜索用时 93 毫秒
1.
2.
番鸭细小病毒分离鉴定 总被引:2,自引:0,他引:2
《中国预防兽医学报》2000,(Z1)
采集以腹泻、呼吸困难为主要症状的雏番鸭肝、脾病料,接种14日龄非免疫番鸭胚,80%胚在3-7天死亡,胚体呈弥漫性充血、出血。接种番鸭胚成纤维原代细胞72小时可见细胞圆缩、聚团等变化。聚苯乙烯乳胶凝集试验呈阳性,提取病毒接种细胞及尿囊液 DNA,用自行设计引物扩增到与设计相符的 600bp片段,克隆至 T载体,经酶切及序列分析表明我们所分离到的病毒为雏番鸭细小病毒(Muscovy Duckiling Pavovirus,MPV)。 相似文献
3.
番鸭呼肠病毒病是发生于雏番鸭(半番鸭)的一种新的急性烈性传染病。病原为番鸭正呼肠病毒,与禽呼肠病毒有一定的抗原相关性;病毒对番鸭胚和鸡胚及其成纤维细胞有致病性,对番鸭和半番鸭有强的致病性,主要感染7日龄~45日龄的雏番鸭,发病率为20%~100%,死亡率为10%~95%以上。临床上以软脚、腹泻、生长障碍为主要症状,病变特征为肝、脾等内脏器官形成大量的灰白色坏死灶。病理组织学变化主要为胸腺、脾和法氏囊的淋巴细胞变性和坏死、单核细胞浸润;肝、脑血管周围和肾间质、肺间质、心肌间有淋巴样细胞或/和吞噬细胞聚集。该病原的致弱活疫苗和灭活苗、以及高免血清可有效防治该病的发生。 相似文献
4.
5.
6.
7.
从鸭体、禽胚和细胞 3个方面探讨了雏半番鸭呼肠孤病毒 FZ2 株的致病性。经试验表明 ,在实验室条件下 ,该株病毒可导致雏番鸭、雏半番鸭发病、死亡 ,对雏番鸭的致死率为 14 .3%~ 4 1.7% ,对雏半番鸭的致死率高达 38.5 % ,且死亡鸭表现出与自然感染呼肠孤病毒病死的雏番鸭、雏半番鸭相同的病变 ;人工感染幸存鸭大多生长发育明显受阻。该株病毒经尿囊腔途径接种 ,对番鸭胚、半番鸭胚、北京鸭胚、SPF鸡胚的致死率分别为 10 0 %、96 %、2 8%和 0 ,致死鸭胚的肝脏、脾脏表面见白色坏死点。经蛋传试验表明 ,该株病毒有可能经胚蛋垂直传染。以该株病毒在番鸭胚成纤维细胞 (MDEF)上连续传接 10代 ,结果细胞病变 (CPE)仍不明显 ,表明其不易适应 MDEF。由此可见 ,该株雏半番鸭源呼肠孤病毒具有较强的致病力 相似文献
8.
从洛江区临床发病鸭分离到2株病毒,2株分离病毒能够致死鸡胚,能被Ⅰ型鸭病毒性肝炎标准强毒高免血清特异性中和。分离毒株在鸡胚上传代培养,并测定ELD50分别为10-6.32/0.2 m L、10-5.49/0.2 m L;经动物回归试验,对1日龄雏番鸭的致死率分别为80%和70%,雏番鸭出现明显的角弓反张姿态,剖检可见肝脏出血斑、出血点,为鸭病毒性肝炎的典型症状,表明分离到的病毒为Ⅰ型鸭病毒性肝炎病毒(DHV-I)。 相似文献
9.
番鸭"花肝病"的病原研究 总被引:2,自引:0,他引:2
从广西患“花肝病”的雏番鸭肝,脾分离到三株病毒,定名为NM1,NM2,NM3。该三株病毒能在番鸭胚和番鸭胚成纤维细胞上增殖。并产生细胞病变,人工感染1日龄番鸭死亡率达100%,但对鸡,康贝尔鸭和鹅不致病。该病毒对氯仿不敏感,耐热,耐酸,不被DNA抑制物所抑制。经超薄切片,磷钨酸负染,电镜观察到大量球形,实心(少量空心)病毒粒子,其大小为66-70nm,该病毒无囊膜。这是一株无囊膜的RNA病毒,其具体的生物学分类位置有待进一步研究。 相似文献
10.
11.
12.
13.
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
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.
17.
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
18.
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
19.
家兔作为一种实验动物 ,推动了繁殖技术的发展。本试验通过对不同年龄公獭兔的睾丸进行组织学观察、测定 ,研究精子的发生规律 ,为系统地进行繁殖生理工作提供依据。1 材料与方法选 60日龄、75日龄、90日龄 3个年龄公獭兔各5只 ,用外科手术法摘取两侧睾丸 ,放入 Bouin氏液中固定 ,二甲苯透明 ,石蜡包埋 ,切成 5~ 8μm切片 ,H.E.染色。在显微镜下观察 ,并进行定量组织学指标测定及差异性比较。2 结果和讨论2 .1 睾丸定量组织学指标的测定结果 见表 1。表 1 獭兔睾丸定量组织学指标 μm,个 /精细管60日龄 75日龄 90日龄曲细精管… 相似文献
20.
Fractures of the anconeal process of 5 pigs ranging in age from 4 to 8 months were studied radiographically and histologically. Clinically, animals with a fracture of the anconeal process had a "tight," restricted gait. In pigs at 4.5 months of age, a radiolucent line through the base of the anconeal process was composed of fibrocartilage, fibrous connective tissue, and hyaline cartilage. Subperiosteal proliferation of woven bone was located along the cranial surface of the olecranon, adjacent to the base of the anconeal process. In older animals, the radiolucent line through the anconeal process contained variable amounts of fibrous connective tissue and fibrocartilage. The proliferation of subperiosteal bone at the base of the anconeal process formed a "buttress callus" which retained a radiolucent area between the callus and the proximal surface of the anconeal process. The latter region of radiolucency was continuous with the transversely oriented line that traversed the base of the anconeal process. 相似文献