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两种粗酶制剂对肉鸡生产性能的影响 总被引：1，自引：0，他引：1
选用６００只１日龄石岐杂肉鸡，随机分成对照和试验两组ＣＥ１与ＣＥ２，每组两重复。饲以玉米基础日粮，ＣＥ１组添加０１％由木聚糖酶、β－葡聚糖酶、果胶酶与蛋白酶组成的酶制剂Ⅰ，ＣＥ２组添加０１％含淀粉酶、蛋白酶与纤维素酶的酶制剂Ⅱ，试验期６０ｄ测定生产性能及有关消化器官参数。结果显示，ＣＥ１和ＣＥ２组鸡全期平均增重较对照组鸡分别提高７０９％和５５９％，料重比分别下降６５１％和５２１％，相对生长的增加持续到中期；三组的小肠相对长、胰腺相对重和死亡率无显著差异。 相似文献
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1 发病情况 2002年1～9月份我们对豫北地区26个商品肉鸡场60批肉鸡的大肠杆菌病调查,有51批发生了大肠杆菌病,发病率为85％、死亡率在6％～17％,如有继发或混合感染,死亡率高达50％,病鸡发病日龄多在14～35日龄,临床症状主要是以拉 相似文献
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近年来，新疆石河子地区鸡传染性法氏囊病的发生较为频繁，而且与以往的发病情况发生了较大变化，主要表现为以下几点。3～5周龄的鸡较多发，而且白羽肉鸡、黄羽肉鸡的发病率比蛋鸡高：发病鸡群的死亡率不大，一般发病率10％～加％，死亡率5％～8％左右。个别发病严重的鸡群死亡率在10％-15％左右：首免使用法氏囊中毒偏强疫苗的鸡群在免疫后2～3天，有个别死亡现象， 相似文献
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陈新 《国外畜牧学(猪与禽)》1999,(5):32-34
肉鸡饲养场的目标是以尽可能低的成本生产出生长良好而均一的肉鸡。在这方面，肉鸡群的均一度在获取高额经济回报中起着重要作用。鸡农最常抱怨说鸡群中８０ ％ 个体的体重为１８ 千克而２０ ％ 个体的体重仅为１４ 千克。对于有１０００ 只鸡的鸡群来说，这位鸡农就已经损失了８０ 千克的活重 相似文献
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肉鸡养殖对于我国鸡养殖产业的发展具有深刻影响.在夏季肉鸡养殖过程中,受温度高、湿度大、致病菌因素多样等因素的影响,肉鸡群中容易发生多种疾病,如球虫病、肉鸡法氏囊等,这些疾病具有较高的发生率和死亡率,其中球虫病的死亡率高达70％～80％,而肉鸡法氏囊疾病的死亡率达到30％～70％,这严重地影响了肉鸡养殖的效益.基于此,有必要做好夏季肉鸡养殖过程的系统管理,积极预防各类肉鸡疾病,提升肉鸡养殖的整体效益. 相似文献
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一流行特征我市鸡马立克氏病发生情况分析有以下特征：１发生品种主要为蛋鸡（罗曼等）发生较多，其次为农村土种鸡，再次为肉杂鸡，基本上没见肉鸡发生过。从发生趋势上看，土鸡、肉杂鸡发生呈上升态势。２发病年龄４周龄到３０周龄不等，但以８周龄到２０周龄居多。３发病季节四季都有发生，但以夏秋季居多。４发病率和死亡率发病率差异较大，一旦发生迟早要死亡。接种疫苗的蛋鸡发病率在５％－１０％之间，往往损失较大，多数情况下只有淘汰。土鸡或肉杂鸡，一般不接种疫苗，发病率在１０％左右。二临床症状我市鸡马立克氏病临… 相似文献
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肉鸡腹水症是由多种致病因子，造成鸡慢性缺氧、代谢机能紊乱等而引起的一种以腹腔内储留大量积液为主要特征的疾病。是进入80年代以来在世界范围内流行较快的新的肉鸡非传染性疾病。主要危害快速生长幼龄鸡，当今成为世界性肉鸡饲养业的严重问题。1发病规律与临床特点该病全年都有发生，但多见于冬春低温舍饲季节。肉鸡发病多在4－6周龄，有时发生在2－3周龄，生长快的雄性鸡县易感，发病率因各地环境因素不同而异，鸡群发病率一般达3％－5％，严重可高达切仍以上，患病鸡死亡率约ho％以上。肉鸡发病初期临床症状不明显，后期腹部肿大，腹… 相似文献
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鸡慢性呼吸道病(又称支原体病)和鸡大肠杆菌病，是近几年肉鸡场的常见病和多发病，3～7周龄鸡最容易感染。特别是在空气流通差。天气阴冷时更容易发病。由于同属条件性、接触性传染病，两病既可并发又能继发，虽呈散发性慢性经过，但死亡率可达20％以上，病鸡治愈后生长缓慢、饲料报酬低。是目前危害肉鸡饲养业的严重疾病。2005年4月28日，山东聊城某养殖户饲养肉鸡2000只，20日龄发病。死亡率达22％。经我中心诊断结果为慢性呼吸道病和大肠杆菌混合感染，现将发病及治疗情况汇报如下。 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