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水貂丹毒是由猪丹毒杆菌引起的急性败血性传染病。本病主要侵害架子猪 ,毛皮兽中水貂最易感染。病貂和带菌动物(猪、鼠类、鸽子、家兔 )是水貂丹毒的主要传染源。食用污染丹毒杆菌的畜禽、鱼类及其加工副产品也会感染。患过丹毒的水貂 ,可产生较强的免疫力 ,一般不会发病。但病愈后长期带菌 ,向外界环境不断排菌 ,引起其他水貂及动物发病。因此 ,饲养水貂的养殖户必须重视水貂丹毒的防治 ,否则会造成水貂丹毒的大面积发生和死亡 ,给养貂户造成严重的经济损失。1 主要临床症状患病水貂精神沉郁、萎靡不振、食欲减少或废绝。口腔、鼻腔、结膜… 相似文献
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毛皮动物(狐、貉、貂)为肉食动物,动物性蛋白质饲料在其饲料中所占比重较大,但随着我国狐、貉、貂养殖量的增加及用于毛皮动物养殖的海杂鱼资源的减少,毛皮动物主要饲料原料鲜海杂鱼、鲜肉及畜禽下杂等产品的价格逐渐升高,导致养殖成本上升。目前以鱼粉、肉骨粉、谷物性饲料等为主要原料的毛皮动物干粉或颗粒全价饲料、配合饲料及浓缩饲料逐渐被广大养殖户接受和使用。用于饲养毛皮动物(狐、貉、貂)的饲料种类很多,一般习惯于把狐、貉、貂的饲料分为动物性饲料、植物性饲料。在此,把常规饲料原料作为毛皮动物饲料使用时应注意的事项做一简要概述。 相似文献
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水貂三大病毒性传染病的发病特点 总被引:3,自引:0,他引:3
随着社会经济的发展,人们对裘皮的喜爱,促使毛皮饲养业得到迅猛的发展。水貂作为一种肉食性珍贵的毛皮动物,在世界各地的养殖业也迅速发展。由于饲养的数量地点及个体饲养户不断增加,种兽频繁交换,运输、加工等给一些传染病的蔓延流行提供了条件。水貂犬瘟热、阿留申病和病毒性肠炎三大病毒性传染病,给水貂养殖业造成了巨大的经济损失。 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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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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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
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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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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
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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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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