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张清 《畜牧兽医科技信息》2005,(3):28
随着养鸡业的发展，养鸡从业者饲养管理水平的提高及防疫意识的增强，疫苗的免疫接种作为疾病的预防措施已广为应用。黄羽肉鸡因饲养期较长(95d左右)，在整个饲养期内，在加强饲养管理期的同时，疫苗免疫接种同等重要。而在实际生产中，接种疫苗后未能获得满意的免疫效果的情况时有发生。究其原因，有以下方面： 相似文献
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1发病情况 养鸡户张某在肉鸡饲养服务户购进雏鸡2300只。根据疫病预防程序，7日龄用鸡新城疫IV＋传染性支气管炎H120二联疫苗，按规定剂量点跟、滴鼻。接种疫苗之后立即使用具有抗菌抗病毒的药物，预防激发呼吸道病，连用3～5天。14日龄使用中等毒力的传染性法氏囊炎疫苗饮水免疫，也同时使用药物3～5天预防激发感染。免疫后的第3天鸡群中出现咳嗽、打喷嚏、拉绿色稀粪的病鸡。 相似文献
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目前我市使用的禽流感疫苗均为油乳剂灭活苗,由于油乳剂疫苗使用矿物油作为载体,注射后吸收较为缓慢,肉鸡胸肌注射禽流感油乳剂疫苗0．5ml,30d后才基本上完全吸收,因肉鸡特别是快速型肉鸡饲养时间短,油乳剂疫苗在肌肉中残留,严重影响鸡肉的品质,一定程度上影响了养禽场（户）进行禽流感二免的积极性。因此,在2006年4月开始, 相似文献
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随着肉鸡饲养规模化及专业化程度的不断提高，对肉鸡疫病的防制也显得愈来愈为重要，对细菌及病毒引起的传染性疫病，通过合理的免疫计划及药物防治已能达到理想的效果，而冬春季多发的肉鸡猝死症及腹水症发病率较高，死亡率高，药物治疗效果较差，直接影响饲养效果及效益。 相似文献
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一段时间以来．大棚养鸡户普遍感觉到肉鸡饲养管理难度变大了，病毒病、细菌病、寄生虫病特别多，即使用了疫苗．投服了很多预防性药物．但温和型新城疫、传染性法氏囊炎、肾型或腺胃型传染性支气管炎、大肠杆菌病、慢性呼吸道综合征、球虫病等疾病，常常不期而遏，肉鸡发病以后。 相似文献
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随着我国加入WTO,畜禽产品质量安全与国际接轨,产品质量问题已影响到了国际贸易,特别是世界性的禽流感暴发以后,对于规模化、集约化、高密度饲养的商品鸡场而言,采取综合性的防治措施来预防疾病的发生显得尤为重要。1采用科学的免疫程序,提高机体抗病力特别是针对目前流行的ND变异株的预防,做到有计划地使用疫苗,强制免疫注射,做好疫情监测和免疫效果监测,一般而言,商品肉鸡血清抗体HI效价应在26以上。根据气管上皮细胞存活10～15d左右的原理,我们向农户推荐两种免疫程序,见表1、表2。表1非疫区免疫程序参考日龄(d)110～1216疫苗种类ND… 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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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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Billinghurst RC Brama PA van Weeren PR Knowlton MS McIlwraith CW 《American journal of veterinary research》2004,65(2):143-150
OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis. 相似文献