鸡舍通风在肉鸡饲养中的重要性

鸡舍内的通风换气在肉鸡饲养过程中占有重要的地位，是肉鸡饲养成功与否的关键因素之一。一、通风不良的危害性由于肉鸡的生长速度快，新陈代谢旺盛，并且属于高密度饲养。随着鸡只的不断生长，需要的新鲜空气量也越来越多；排出的粪便也越来越多，产生的有害气体就越来越多，其中对鸡危害最大的气体主要是氨气和硫化氢。氨是无色且具有强烈刺激性气味的气体。氨的比重小，在温暖的舍内一般升至舍顶，但由于氨产生在地面和鸡只周围，故在鸡舍地面含量也较高，特别是在鸡舍内潮湿、通风不良时，舍内氨的浓度就更高了。鸡对氨特别敏感，氨对鸡…     

现代化养鸡场de通风系统

鸡舍的通风换气，是鸡舍环境控制的一个重要手段。通风是鸡舍防热措施的重要组成部分，通过加大通风，可以排出鸡舍产生的热能，不使其在鸡舍积累而导致舍温升高；同时，较快的气流速度，使鸡感到舒适，可以缓和高温对鸡群的不良影响。而换气是指在鸡舍密闭的情况下，引进舍外新鲜空气，排出舍内的污浊空气，以改善鸡舍空气环境质量。一．鸡舍的夏季通风夏季通风，也称通风降温，它主要包括：（１）借助空气的流动，排出鸡舍内多余的热量；（２）在鸡体周围形成气流，以促进鸡的对流散热。鸡实际感受到的温度受环境中湿度、风速的影响很大。…     

鸡舍的通风技术及其进展

鸡舍内环境的状况直接影响到鸡生产性能的发挥，也影响到禽产品的质量，舍内通风则是调控鸡舍内环境的重要方法之一。在对禽产品质量要求日益提高的今天，很有必要对我国目前鸡舍的通风状况进行讨论，以利于生产的发展和质量的提高。１鸡舍通风的作用鸡舍的通风，首先是要让新鲜的空气进入鸡舍，使鸡只随时能呼吸到充足的新鲜空气；其次是通过通风来调节室内的温、湿度；第三是要把鸡舍内的有害气体与有害物质排出舍外。应该被排除的物质主要有：①鸡只呼吸所排出的气体与水分，②机体消化道所排出的有害气体，③鸡粪所散发出的有害气体，④…     

浅析农家鸡舍的通风

随着集约化养鸡业的发展,高密度大规模饲养带来的问题越来越多。特别是鸡舍通风不良,往往造成舍内高温、高湿、高浓度有害气体污染了整个鸡舍。长此下去使鸡体质下降,逐渐诱发各种疾病,使死亡率增高,经济效益降低。为了改变目前的这种状况,现就鸡舍通风的问题做一浅析。 一、存在的问题 据我们对73户个体养鸡户鸡舍通风情况的调查,存在着如下问题: 一是73％的个体养鸡户鸡舍没有通风设备及通风口,舍内通     

加强管理，减少诱因

一消除非传染性因素 一加强饲养管理，注意不要使用发霉的垫料和饲料，保持圈舍的清洁、干燥，垫料要经常翻晒和更换，防止霉菌生长；注意对圈舍进行合理通风换气，减少氨气等刺激性废气的滞留。因氨气刺激会容易使鸡发生呼吸道疾病，是很多鸡呼吸道疾病发生的诱因，应把冬季保温、通风换气和饲养密度有机结合起来，同时要使鸡舍保持合适温度，从而减少外在的诱导因素；解决好通风和保温这对矛盾是减少鸡只在冬季发生呼吸道疾病的关键。     

蛋鸡管理年历(下)

２、夏季管理 炎热的夏季阴雨天增多，而高温高湿对产蛋鸡极为不利，酷暑影响也易造成产蛋率和体质下降，并影响抗病能力。防暑降温，创造条件让鸡群安全渡夏是管理关键。 ２．１入夏前做好准备工作：在舍外搭遮阳棚；绿化和种植高大树木；勤清除舍内鸡粪、减少鸡粪在舍内的产热；自然通风的鸡舍应尽可能地加大通风口，可安装排风设备纵向通风。 ２．２入夏后要加强防暑措施：增大舍内的风速降温，一般风速达到１－１．５米／秒较好；可在舍内喷雾，利用水的蒸发来降低舍温；纵向通风的可在进风口安装湿帘降温；多让鸡饮干净清凉的饮水。 ２…     

春季养鸡注意事项

笔者多年在基层兽医站工作,跟养鸡场工作接触比较多,现将春季养鸡注意事项总结如下：1防寒保暖春天气候寒冷多变,给养鸡生产带来许多不便,特别是昼夜温差较大对产蛋鸡的影响十分明显。此季节应控制好鸡舍温度,使鸡舍昼夜温差不要超过5℃。2适度通风春季由于气温较低,鸡舍门窗关闭较严,通风量减少,但鸡排出的废气和鸡粪发酵产生的NH3、CO2、H2S等有害气体却依然存在,舍内空气污浊时,易诱发鸡的呼吸道等疾病。因此,要切实处理好通风与保暖的关系,及时清除鸡舍内的粪便和杂物,在中午天气较好时,开窗通风,使舍内空气清新,氧气充足。3减少潮湿春季鸡舍内通风量少,水份蒸发量减少,造成鸡舍内过度潮湿,给细菌和寄生虫的大量繁殖创造了条件。因此,一定要强化管理,谨防细菌病、寄生虫病等以免造成不必要的损失,建议：定时添加“百草肠清,肠宝500kg料每代”预防肠炎、大肠杆菌病等细菌病,“肠冠清500kg料每袋”预防肠炎、球虫等。同时建议大家长时间添加“益酶丽维”前5d,每代拌lOOkg料;再5d每袋拌150kg料;长期用每袋拌250kg料,调整鸡只肠道菌群平衡提高饲料转化率、减少肠道疾病的发病率。     

夏季缓解鸡热应激的措施

１安装降温设备在密闭鸡舍安装风机和水帘，采取纵向通风和水帘降温，能使舍温下降７～１０℃，这是一项理想的降温措施；在开放式鸡舍可安装电风扇，利用自上而下的送风方式来降低鸡的体表温度，特别给鸡头部一定的风速，使鸡有凉快感，可保持鸡的正常食欲和采食量，维持产蛋率不下降。在农村的简陋鸡舍，安装电风扇是一个行之有效的降温措施。但是有不少农民在简陋鸡舍安装风机降温，往往窗户开闭不严，空气截流，其降温效果并非十分有用。２自然通风换气在高温季节，开启全部门窗，扩大鸡舍的通风面积，并清除鸡舍周围影响通风的障碍物。…     

饲养肉仔鸡的困难及解决办法

１开始养鸡易，越养越难养原因：鸡舍严重污染。解决办法：鸡舍彻底消毒，严格控制环境。１．１鸡舍消毒，灭菌灭鼠村外建场，全进全出，彻底清除，三次消毒。用１％～３％烧碱水冲洗全舍及器具，并空舍１周；垫粗砂，铺稻壳。用双链季胺盐如百毒杀等喷雾。禽舍封闭升温后用福尔马林２０毫升／米加热熏蒸２４小时。１．２鸡舍保温、通风、干燥平面育雏用火炕、火道保温成本低、成活率高。２喂饲不好鸡不长，腿发白；喂料好了又有腹水，或蹦蹦就死２．１．鸡不长时，生长速度明显达不到品种指标，腿、冠苍白原因：“苍白综合征”即“腿弱综合…     

冬季肉仔鸡饲养管理技术要点

冬季是鸡病的多发季节，气候寒冷、干燥，给肉仔鸡饲养管理带来一定的难度。现将冬季肉仔鸡饲养管理技术要点作一简单介绍，仅供同行参考。１改“地面平养”为“网上架养”冬季气候寒冷，鸡舍地面较凉，采用地面平养的饲养方式容易使鸡受凉而引起腹泻等症状，不利于肠道疾病的控制，尤其是大肠杆菌病、球虫病难以控制。采用“网上架养”具有节省垫料、降低球虫病、大肠杆菌病等疾病的发生、减少应激、易于环境控制等优点，并且使鸡供温均匀，有利于生长。因此，在冬季最好采用塑料棚网上架养。２处理好温度与通风的关系温度是鸡生长发育的主…     

商会自治的基石——商会自治规范研究

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。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

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。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

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.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

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。     

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.     

Mechanism of Action of Probiotic Function of Lactobacilli

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.     

Evaluation of serum concentrations of biomarkers of skeletal metabolism and results of radiography as indicators of severity of osteochondrosis in foals

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.