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三聚氰胺对蛋鸡生产性能影响及其排泄规律的研究 总被引：1，自引：0，他引：1
本试验旨在研究三聚氰胺对蛋鸡生产性能影响及其排泄规律。分两部分进行:试验1,选用28周龄海兰褐壳蛋鸡144只,随机分为3组,每组6个重复,分别饲喂玉米-豆粕型基础日粮(对照组)和三聚氰胺添加水平为50、100 mg/kg的日粮(处理组),测定蛋鸡生产性能和粪样中三聚氰胺、三聚氰酸、消化率的变化;试验2,选用42周龄海蓝褐壳蛋鸡24只,分为2组,每组12个重复,处理组在基础日粮中添加100 mg/kg三聚氰胺,测定蛋鸡不同等级卵泡中三聚氰胺的变化。结果显示,日粮中添加50、100 mg/kg三聚氰胺对蛋鸡生产性能和粪中三聚氰酸的浓度均无显著影响(P0.05);试验1两处理组粪中三聚氰胺的浓度均显著高于对照组(P0.05),两处理组粪中三聚氰胺至停喂三聚氰胺日粮后96 h时仍未消除完毕。试验2在不同等级卵泡中均含有三聚氰胺,且随卵泡发育呈稳定增长趋势。结果表明,日粮中添加50、100 mg/kg三聚氰胺对蛋鸡生产性能无显著影响;三聚氰胺可在体内蓄积并达到稳定状态;可通过粪便及蛋黄排除体外;停喂三聚氰胺日粮96 h蛋鸡体内三聚氰胺仍未消除完毕。 相似文献
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《黑龙江畜牧兽医》2015,(13)
为了研究三聚氰胺与三聚氰酸联合导致蛋雏鸡肝脏氧化损伤,试验分别在基础饲料中添加30 mg/kg三聚氰胺+10 mg/kg三聚氰酸(低剂量组)和50 mg/kg三聚氰胺+16.7 mg/kg三聚氰酸(高剂量组),饲喂8日龄蛋雏鸡,在第7,14,21,28,35,42天宰杀鸡群(每次每组8只),取肝脏提取蛋白,检测蛋白浓度、总超氧化物歧化酶(T-SOD)活性、丙二醛(MDA)含量。结果表明:三聚氰胺与三聚氰酸联合作用后第1~5周内,试验组T-SOD活性差异不显著(P0.05);第6周试验组TSOD活性低于对照组,低剂量组差异极显著(P0.01),高剂量组差异显著(P0.05)。第1~6周试验组MDA含量与对照组相比差异不显著(P0.05)。说明三聚氰胺与三聚氰酸联用可显著增加肝细胞线粒体损伤,但对法氏囊组织细胞生物膜损伤不明显。 相似文献
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三聚氰胺致大鼠肾损伤模型的研究 总被引：2，自引：0，他引：2
目的为三聚氰胺肾损伤的研究建立动物模型。方法刚断乳的清洁级Wistar大白鼠,在清洁级动物室喂饲含三聚氰（50mg／kg·bw／d）的饲料,4周后处死动物做血液生化检测、脏器系数计算,取肾组织进行石蜡包埋、制片、HE染色,进行病理组织学检查。24h尿量计算。结果大鼠经口喂饲含三聚氰胺（50mg／kg·bw／d）的饲料,可在大鼠肾内形成结晶体,并致肾脏特征性病理改变。结论大鼠经口喂饲含三聚氰（50mg／kg．bw／d）的饲料,可致严重肾损伤,结果可重复,成功建立三聚氰胺致肾损伤动物模型。 相似文献
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三聚氰胺对雌性Wistar大鼠的慢性毒性研究 总被引：1，自引：0，他引：1
三聚氰胺（melamine,MA）对小鼠的经口LD50为4550mg/（kg.bw）,急性毒性属于低毒物质。为证实和客观评价其慢性毒性,以每千克饲料500、1000和2000mgMA/kg饲料的剂量对6周龄雌性Wistar大鼠进行了6个月慢性毒性试验。结果表明,各剂量组雌性Wistar大鼠肾、肝和膀胱均有不同程度地功能异常和器质性病变;血液ALT、AST、CRE和UA等生化指标均有不同程度地升高,肾、肝和膀胱黏膜均有不同程度地病理变化或损伤;每千克饲料2000mgMA/kg饲料的剂量能够抑制大鼠生长和采食,肾病理变化显著,出现结石;染毒组大鼠脾脏、骨髓等未见病变;MA对大鼠的最大无作用剂量应小于（35.7±15.4）mg/（kg.bw.d）。 相似文献
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将80只昆明小白鼠随机分为4组（每组20只）：空白对照组（Ⅰ组）、三聚氰胺高剂量组（300mg／kg）（Ⅱ组）、三聚氰胺中剂量组（150mg／kg）（Ⅲ组）和三聚氰胺低刺量组（37．5mg／kg）（Ⅳ组）,试验周期为30d。试验期内观察小白鼠一般情况、体质量变化及食物利用率。结果显示：三聚氰胺染毒组小鼠体增重缓慢,食物利用率极显著降低（P〈0．01）;Ⅱ、11组小鼠血清ALT、AST、BUN、Cr和UA值显著高于Ⅰ组（P〈O．05）,Ca和P显著低于Ⅰ组（P〈0．05）;Ⅱ组小鼠肝、肾指数显著高于I组（P〈0．05）,Ⅱ、Ⅲ组脾指数显著低于Ⅰ组（P〈o．05）;Ⅱ、Ⅲ组小鼠肺、肝、脾、肾及膀胱有病理变化。结果表明,三聚氰胺亚慢性毒性会影响动物生长,造成肺、肝、肾及脾损害。 相似文献
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《中国家禽》2017,(11)
试验旨在研究三聚氰胺对肉鸡的亚慢性毒性。选取120只1日龄健康AA肉鸡,随机分成5组,第1组为对照组,第2~5组为试验组,分别饲喂含三聚氰胺0、40、120、360和1 080 mg/kg的饲料,试验期为60 d。结果表明,肉鸡摄入含三聚氰胺360 mg/kg和1 080 mg/kg的饲料,出现明显的中毒症状和死亡,肉鸡料重比、平均日增重极显著低于对照组(P0.01);血浆丙氨酸氨基转氨酶(ALT)和天门冬氨酸氨基转氨酶(AST)活性、血浆肌酐、尿酸含量以及肝脏和肾脏指数显著高于对照组(P0.05)。肉鸡摄入含三聚氰胺40 mg/kg和120 mg/kg的饲料,其生产性能、血液生化指标及脏器指数与对照组无明显差异(P0.05)。由此可见,肉鸡摄入饲料中三聚氰胺含量高于360 mg/kg可发生三聚氰胺中毒,中毒靶器官是肝脏和肾脏;饲料中三聚氰胺对肉鸡的无可见有害作用水平为120 mg/kg。 相似文献
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《中国畜牧兽医》2010,(12)
本试验旨在研究口服1次三聚氰胺,其由饲料向牛奶中排出形式,以及随后由牛奶向干酪和乳清中的转化。同时对于三聚氰酸的转化进行了研究。24头泌乳荷斯坦奶牛随机分为4个处理,设定为D1、D2、D3和D4组,各组奶牛仅饲喂1次三聚氰胺,饲喂量分别为0.05、0.50、5.00和50.00 g/d。试验第1、2、3、4、5、7天采集牛奶样品测定其中三聚氰胺和三聚氰酸含量。摄入三聚氰胺后第2次采集的奶样用于实验室条件下制作干酪。三聚氰胺和三聚氰酸采用固相萃取柱萃取,并利用液相色谱/串联质谱法进行测定。处理后第6至18 h三聚氰胺浓度最高并呈对数(线性和二次)上升,范围在0.019～35.105 mg/kg之间。三聚氰胺摄入30 h后,60%以上的三聚氰胺转移至乳中。D1组奶牛饲喂后第5天其乳中三聚氰胺含量低于检出限(检出限0.002mg/kg),而D2、D3和D4组奶牛饲喂后7 d乳中三聚氰胺含量低于检出限。血尿氮不受摄入三聚氰胺影响。制作干酪过程中,三聚氰胺主要转移至乳清中。奶牛乳中、干酪或乳清中均未检出三聚氰酸。当奶牛每天摄入0.50 g三聚氰胺时,其排出方式为乳和乳清,可能引起人们对健康的关注。但只有摄入量为5和50 g/d时,干酪中三聚氰胺含量超过欧盟规定限量。本研究结果说明,三聚氰胺污染乳和乳制品也许既与直接污染有关,同时也与动物饲料掺假有关。 相似文献
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本研究采用组织病理学和免疫组织化学技术观察了三聚氰胺（Melamine,MA）对雄性小鼠睾丸的毒性作用,以深入揭示三聚氰胺的毒性作用及其机理。将25只28日龄SPF雄性昆明小鼠随机均分为5组,1组为对照组,其他4组为试验组。4个试验组分别按下述不同剂量灌服三聚氰胺：0.6 mg/kg（bw）/d（每日每公斤体重0.6 mg）、3.0 mg/kg（bw）/d、15.0 mg/kg（bw）/d和17.5 mg/kg（bw）/d,用玉米油做溶剂;空白对照组每日灌服等量玉米油。连续灌胃30天后剖检小鼠并取其睾丸组织进行固定、切片和染色,观察睾丸的组织病理变化。同时,采用免疫组织化学方法检测睾丸组织中增殖细胞核抗原（PCNA）的表达量。观察结果表明,与对照组相比,试验组不同剂量浓度的三聚氰胺对小鼠睾丸组织造成不同程度的病理损伤;三聚氰胺也会在一定程度上影响睾丸组织中PCNA的表达。研究结果表明三聚氰胺对于小鼠生殖系统有明显毒性作用。 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