霉菌毒素对家禽的危害及降解技术

家禽对霉菌毒素敏感,多种霉菌毒素对家禽都存在毒害作用。本文介绍了家禽黄曲霉毒素、单端孢霉烯族毒素、玉米赤霉烯酮、赭曲霉毒素和烟曲霉毒素中毒的主要症状,以及家禽饲料中霉菌毒素脱毒的方法。     

霉菌毒素对家禽机体代谢的影响

所有从事家禽生产者几乎都知道家禽饲料中可能带有的霉菌毒素.霉菌毒素是由霉菌产生的化学物质,对家禽有毒.霉菌毒素的负面影响与毒素的性质、浓度、饲喂时间、家禽的日龄、营养状况以及应激因素有关.普通的霉菌毒素对所有家禽内脏器官均有特异性病理影响,引起最常见的症状和损害.毒素几乎影响所有的机体器官,但在生产实际中表现的常见症状总是与这些器官的功能有关.     

养禽生产应重视霉菌毒素

关于霉菌和霉菌毒素的危害在养猪业中的研究较深入．祛霉脱霉技术的应用比较普遍。主要原因是霉菌毒素对猪造成了可见的病理变化和临床症状以及更直观的经济损失,如母猪不发情、假发情、不孕、流产、死胎等。霉菌及霉菌毒素给养禽业也造成了较大经济损失．但人们往往会忽视其对家禽的影响。     

霉菌毒素对家禽的毒性效应及其防控措施

在当前规模化养殖背景下，家禽饲料及其原料霉变是影响家禽养殖业发展的一大重要问题。家禽通过食源途径长时间或大剂量地摄入黄曲霉毒素、呕吐毒素及玉米赤霉烯酮等霉菌毒素后会引起机体多系统的毒性效应，如降低生产与生长性能，损伤肝肾等代谢器官，破坏机体免疫机能等。其诱发毒性作用的机制主要涉及促使氧化还原系统失衡，触发炎性反应，影响细胞死亡或自噬等。可以采取干预家禽霉菌毒素中毒诱发的损伤，抑制霉菌繁殖或产毒，合理脱毒等综合措施防控家禽霉菌毒素中毒。本文就霉菌毒素对家禽的毒性作用与机制及其防控措施等进行了概述，以期为家禽的健康养殖提供科学依据。 [关键词] 霉菌毒素|家禽|氧化应激|免疫功能|作用机制     

家禽霉菌毒素中毒的病型分析和防治措施

在家禽饲养过程中,霉菌毒素是影响其生长发育的主要因素之一。基于此,本文简要分析了家禽在生长过程中可能会遭遇的各种霉菌毒素,并有针对性地提出一些解决方案,希望能够给同行带来一定的帮助。     

饲料中霉菌毒素对家禽的影响

作为养禽业的主要饲料原料 ,玉米、豆饼（粕）等 ,从田间生长、收获、贮藏、加工等一系列过程中 ,都可被霉菌所污染。霉菌在适宜条件下生长代谢、繁殖时 ,一方面分解饲料中的营养物质 ,另一方面排出一些代谢产物 ,包括霉菌毒素。受到霉菌污染的饲料不仅饲料品质和营养价值降低 ,而且某些霉菌产生性质不同的霉菌毒素 ,可引起家禽生长速度减缓、饲料转化率降低 ,出现急性或慢性中毒 ,消化、呼吸、免疫、生殖机能等受损。同时 ,残留在肉、蛋等畜产品中的霉菌毒素及其代谢物还会对人类健康造成极大的潜在危害。由于不同性质的霉菌毒素对家禽的影…     

霉菌毒素对家禽机体代谢的影响

所有从事家禽生产者几乎都知道家禽饲料中可能带有的霉菌毒素。霉菌毒素是由霉菌产生的化学物质，对家禽有毒。霉菌毒素的负面影响与毒素的性质、浓度、饲喂时间、家禽的日龄、营养状况以及应激因素有关。普通的霉菌毒素对所有家禽内脏器官均有特异性病理影响，引起最常见的症状和损害。毒素几乎影响所有的机体器官，但在生产实际中表现的常见症状总是与这些器官的功能有关。     

霉菌毒素中毒的预防方法

霉菌毒素可危害家禽健康，而肉、蛋的霉菌毒素残留则可危害人类健康。霉菌毒素进入机体会扰乱代谢然后又发生生物转化。要预防霉菌毒素中毒就必须限制机体对其的吸收，要预防其对代谢的扰乱，要激发内源性解毒作用的发生。     

饲料中的霉菌毒素损害家禽免疫机能

霉菌毒素是由真菌（霉菌）产生的一系列化学性质各异的化合物的总称,是家禽饲料中常见的污染物。对家禽生产造成经济损失的霉菌毒素有：黄曲霉毒素（Aflatoxins）、赭曲霉毒素（Ochratoxins）、单端孢菌毒素（Trichothecenes）、玉米赤霉烯酮（Zearalenone）和烟曲霉毒素（Fumonisins）（Hussein和Brasel,2001）。据估计,全球25％以上的谷物都不同程度地遭受霉菌毒素的污染,对家禽养殖业造成了很大经济损失。     

家禽的霉菌毒素中毒症

家禽饲料中植物原料占一大部分。因此这些植物原料即使偶而受到霉菌毒素的污染也会引起严重后果。此外,现代家禽品种和杂交种的产蛋性能和产肉性能很高,机体的代谢率也就较高,因此对包括霉菌毒素在内的饲料质量不足的忍受力较低。     

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.     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

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。