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2003年4月中旬,济宁某种鸡场连续孵化3批种蛋,孵化期间均发生大批胚胎死亡,出壳的雏鸡表现弱雏,成活率极低.经询问种鸡饲养状况和观察死亡胚、死亡雏鸡的症状,确诊为种鸡维生素B2缺乏症. 相似文献
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发病情况及临床症状：2004年9月，我市一孵化场连续4批种蛋孵化率突然由94％降到73％，弱雏明显增多，但选出的雏鸡精神状态基本正常，没有明显的临床症状。弱雏则表现瘫痪或站立不稳，跗关节红肿，售出的雏鸡于2日龄出现精神萎靡、喜卧，不采食。有时出现高度神经质，部分雏鸡在奔跑中步态不稳，向前猛冲后跌倒，有的雏鸡被踩踏而死亡，个别雏鸡出现头颈震颤症状，3日龄时死亡率达57％。根据临床症状，初步怀疑是禽脑脊髓炎，并在之后出雏的3批32000只雏鸡中细心观察，仅发现5只雏鸡有典型头颈震颤症状。之后对种鸡场进行了解，种鸡出现场产蛋率由93％下降到63％，但采食、粪便、蛋色及种鸡的精神状态均正常。 相似文献
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孙海波 《广东畜牧兽医科技》1999,24(2):50-50
家禽（主要指鸡）的胚胎病造成的危害主要有三个方面：一是导致一部分胚胎死亡,降低出雏率;二是病旺孵出的病雏、弱雏,生长发育和成活率都远不及健维;三是种鸡某些传染病（如白痢病）的病原微生物通过种蛋带菌──病胚──病雏的途径广为扩散。胚胎病可以分为三类,即由种蛋缺乏某些维生素和矿物质引起的营养性胚胎病;由母源或外源微生物引起的传染性胚胎病;由孵化措施不当引起的胚胎发育不良或异常。目前,胚胎病的治疗措施不多,重点在于预防。1营养性胚胎病表现为胚胎发育不良,严重时造成死胚。程度较轻的可以孵出雏鸡,但体质较… 相似文献
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1发病情况新疆霍城县六十四团某饲养户2001年饲养种番鸭320只,一直无疫情,于2002年5月开始用水炕自孵雏番鸭105只,同炕还孵化出雏鹅、雏鸡、雏火鸡等,当雏鹅7日龄时,售后余下的10只雏鹅开始发病,死亡8只,死亡率为80%,同时,售后余下的30多只雏番鸭相继开始病死,而同舍饲养的雏鸡、雏火鸡均健康。此后又孵化雏番鸭四批约2000只,均在7～13日开始陆续发病,死亡率在36.5%～65%之间,平均死亡率达51%,发病期间曾用氟哌酸、左旋氧氟沙星、炎瘟清、氯霉素、土霉素等药物治疗均无效。2临床症状6～13日龄为易发期,雏鸭突然发病,迅速波及全群,患鸭表现精… 相似文献
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<正>鸡白痢是由鸡白痢沙门氏菌引起的传染病,在雏鸡通常表现急性全身性感染,在成年鸡则以局部和慢性感染为主。鸡白痢可造成严重经济损失,有的鸡群死亡率可达到100%。经卵传播是本病最常见的传播方式,如果种鸡发生鸡白痢感染,在孵化和出壳期间可以出现死胚、死雏和弱雏。孵出雏鸡往往在第2周内出现症状,死亡高峰在2～3周。本病也可水平传播,需要持续不断 相似文献
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小日龄种蛋(160～200日龄种鸡生产的种蛋)的孵化是困扰孵化场的瓶颈之一,虽然小日龄种蛋孵化的雏鸡表现产蛋率高、产蛋高峰期维持时间长等优点,但在孵化过程中存在出雏拖延时间长、雏鸡个体差异偏大等问题。因而,在小日龄种蛋的孵化方面,提高雏鸡的出雏整齐度以及雏鸡的成活率是孵化工作的重点。 相似文献
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1 孵化期胚胎死亡的分布规律
发现胚胎死亡在整个孵化期不是平均分布的,而是存在两个死亡高峰;第一个高峰期出现在孵化前期,鸡胚在孵化第2d至第5d,死胚率约占全部死胚数的15％：第二个高峰期出现在孵化后期,鸡胚在孵化第18d以后,约占全部死胚数50％。青海省大通县种鸡场鸡孵化多使用罗曼、京黄、伊莎褐等高孵化率种鸡,死胚多出现于第二高峰期。 相似文献
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<正> 新疆华新禽蛋公司正兴建着规模两万只种鸡场、20万只商品蛋鸡场和孵化厅。动工以来至1984年4月已完成雏鸡舍二栋、种鸡舍四栋及兽医室、消毒室、变电室、锅炉房和门卫室等附属建筑。于3月8日从北京市第二种鸡场运去第一批初生雏7,800只,途中死亡36只;3月13日运去第二批5日龄雏2000只,途中死亡37只;3月20日又运进5日龄雏 相似文献
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用 3批AE (AvianEncephalomyelitis)油佐剂灭活疫苗免疫开产前种鸡 ,免疫后定期采集种蛋进行孵化。当孵至 6日龄时取部分鸡胚 ,卵黄囊途径接种AEVVR株 ,进行AE鸡胚易感性试验。剩余鸡胚孵化至出雏后 ,分别于 1 ,7,1 4 ,2 1日龄肌肉注射AEVVR株攻毒。攻毒后观察不同日龄子代雏鸡AE的保护能力。结果疫苗免疫后 2～ 3个月的种鸡所产种蛋胚对AEV保护率达 1 0 0 % ,而同期所产种蛋孵出的子代雏鸡 ,在出雏后 3周内对AEVVR株攻毒的保护率亦达 1 0 0 %。免疫后 6～ 7个月种鸡所产种蛋胚对AEVVR保护率达 75 %～ 80 % ,而同期所产种蛋孵出的子代雏鸡 ,在出雏后 3周内对AEVVR株攻毒的保护率达 70 %～ 90 %。试验结果表明 ,AE鸡胚易感性试验的鸡胚保护率与同期雏鸡对AEVVR肌肉注射攻毒的保护率基本相同 相似文献
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文登市一肉鸡饲养专业户干1998年4月5日购进"AA"商品肉鸡苗2400只,采用地面搭棚上架问养。为了提高雏鸡的成活率,促进生长,改善调料转化率,该专业户在肉鸡颗粒全价饲料中添加咦乙醇0．25％。雏鸡4日龄前生长状况尚可,到5日龄部分雏鸡出现中毒症状,并且开始死亡,以后死鸡数逐日增多。至8日龄,中毒鸡达1800多只,占鸡群的75％。死t970多只,死亡率达40．5％。急性中毒雏鸡突然死亡;慢性中毒雏鸡精神沉郁．行走不稳,腿爪外伸．有的侧卧,打颤,部分雏鸡是犬坐姿势,伴有呼吸困难症状。剖检死雏24只,活雏6只。死雏咦囊内充满食物,… 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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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
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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