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《养殖与饲料．饲料世界》2021,(10)
正鸡羽虱病一般由鸡皮肤表面寄生虫或细菌所引起。患有此病的鸡表现为奇痒,甚至鸡因为自身过于难受而啄掉自己的羽毛,导致掉毛现象。患羽虱病的鸡还会逐渐消瘦,不爱食,整天啄毛或抖动自己的羽毛,另外雏鸡生长发育受阻,母鸡则产蛋率下降或干脆不产蛋。以下是治疗鸡羽虱病的2个方案,如果大范围鸡患此病,建议使用,效果比较好。 相似文献
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鸡羽虱寄生于鸡体表,以食宿主的羽毛或皮肤为生。羽虱的大量寄生,使鸡奇痒不安,羽毛脱落变稀,严重影响鸡的生长发育、增重和产蛋。我所鸡场笼养鸡一直使用敌杀死防治鸡羽虱,效果显著。其方法是:将1瓶 相似文献
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鸡在生长过程中有换羽的习惯,鸡的羽毛从出壳至成年,要经过三次更换。这属于正常的生理现象。但是现代笼养蛋鸡在生产过程中往往出现非生理现象的脱羽现象,对鸡的越冬、生长和生产(羽被是一个影响采食量的重要因素)造成了一定的影响。研究脱羽问题可以从疾病、管理、营养等方面进行研究,下面作以分析。1脱羽的原因1.1疾病因素皮肤寄生虫可以引起脱羽,如羽虱、羽螨引起的羽毛折断而引起脱羽。鸡虱以羽毛、绒毛以及皮肤鳞屑为食。鸡受到虱体严重侵袭而发生奇痒和不安,患鸡因啄痒而啄断自体羽毛或啄伤皮肉。鸡膝螨病虫体沿羽轴穿入皮肤,致局部… 相似文献
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对榆林地区鸡的虱类进行了较为详细的调查。获得和已鉴定的虱类有6种，分别为：鸡短角羽虱（Menopon gallinae)，草黄短角羽虱（M.stamineus)。异形长羽虱（Lipeurus heterographus)。草黄短角羽虱（M.stamineus)。异形长羽虱（Lipeurus heterographus)。阉鸡长羽虱（L.caponis)，鸡圆羽虱（Goniocotes gallinae)。不同角羽虱（G.dissimilis)。并对以上各虱种的寄生部位，形态特征和地理分布进行了观察和描述。 相似文献
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郜峰 《上海畜牧兽医通讯》2009,(6):120-121
鸡羽虱是鸡体最常见的外寄生虫,属于羽虱属昆虫纲食毛目毛虱属,有40多个种。鸡的羽虱以种类不同分别寄生于鸡的肛门下、胸、背、翅（体虱）;头、颈（头虱）和羽干（羽虱）等处。虽然寄生部位略有差异,但均通过直接或间接接触性传播,在啮食鸡体表皮肤、皮屑时造成鸡的奇痒不安,以及自相啄痒而致皮肤损伤、羽毛残脱,食欲下降,生长发育受阻, 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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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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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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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