原子荧光和原子吸收测定饲料中铅的对比

采用硝酸-盐酸-氢氟酸混合酸湿法消解的前处理方法,应用原子荧光光谱仪和火焰原子吸收光谱仪测定饲料中的铅,对精密度、回收率等方法评价指标进行分析,结果显示:原子荧光光谱仪和原子吸收光谱仪测定铅的含量分别为5.735、5.838 mg/kg,检测精密度分别为4.19%、3.91%,方法检出限分别是0.032μg/kg、0.098 mg/kg。2种仪器测试结果一致,都适用于饲料中铅的测定。     

梅花鹿“晃腰病”发病鹿场鹿用饲料分析

梅花鹿“晃腰病”发病鹿场鹿用饲料的种类与我国东北地区一般鹿场基本一致。饲料的品质及用量符合饲养管理技术标准。饲料微量元素平衡失调。其中玉米Cu含量1.52±0.11mg/kg,玉米秸Cu含量2.89±0.09mg/kg,青贮玉米叶Cu含量2.14±0.26mg/kg,大豆Cu含量6.85±0.34mg/kg,柞树叶Cu含量7.63±0.49mg/kg,均显著低于同期健康鹿场同种饲料。Fe元素含量没有显著变化,表明病鹿高Fe血症及肝Fe含量升高与饲料无关。饲料Zn、Mn含量显著升高。Mo、Co、Cd、As、Hg、Ag等微量元素含量与健康对照鹿场饲料间没有显著差异。     

饲料铅胁迫对吉富罗非鱼生长性能及肝胰脏抗氧化能力的影响

本试验旨在研究饲料铅对吉富罗非鱼生长性能及肝胰脏抗氧化能力的影响。试验选用200尾全雄吉富罗非鱼,初始体重为(14.44±3.82)g随机分为2个组,每个组4个重复,每个重复25尾鱼,分别投喂铅添加水平为0和800 mg/kg的饲料,试验期为28 d。结果:饲料铅显著降低了吉富罗非鱼的增重率、特定生长率和蛋白质效率(P0.05),并显著提高了饲料系数(P0.05);饲料铅胁迫组的丙二醛水平显著升高(P0.05),总抗氧化能力水平与过氧化氢酶活性显著降低(P0.05),超氧化物歧化酶活性与对照组相比无显著差异(P0.05)。800 mg/kg的饲料铅胁迫可降低吉富罗非鱼的生长性能,导致肝胰脏抗氧化能力下降。     

饲料中铅的测定改进

铅是一种有害元素,畜禽连续摄入铅超过安全范围,会通过损害神经系统、造血器官和肾脏危及健康。同时,铅在畜禽体内蓄积通过食物链也影响人体健康。饲料是动物铅的主要来源,我国饲料卫生标准GB13078中规定了各种饲料铅的允许量范围,自1991年起还发布实施了饲料中铅的测定方法国家标准GB/T 13080—1991。该标准存在灰化时间过长、萃取不完全、不易操作等缺陷。因而探讨更快捷准确测定饲料中铅的方法非常必要。本文结合对GB/T 13080—1991的修订,探讨     

饲料级蛋氨酸镧制备条件的研究

对蛋氨酸镧饲料添加剂生产中的酸度、原料用量、温度、反应时间等进行了研究,并研究出一条最佳合成路线。经测定,蛋氨酸镧饲料添加剂中镧的含量为32.4%(>30%),对动物有害的元素(铅、汞、镉、砷)的含量分别小于0.2、0.5、1.0、0.75mg/kg;符合国家食品卫生标准。     

原子吸收法检测鱼粉中铅含量的探讨

我国饲料卫生标准中规定：鱼粉、石粉、骨粉、肉骨粉中的铅含量（以Pb计）≤10mg／kg;磷酸盐≤30mg／kg;鸡配合饲料、猪配合饲料、生长鸭、产蛋鸭、肉鸭配合饲料≤5mg／kg;产蛋鸡、肉用仔鸡浓缩料,仔猪、生长肥育猪浓缩料≤13mg／kg;奶牛、肉牛精料补充料≤8mg／kg;产蛋鸡、肉用仔鸡复合预混合饲料,仔猪、生长肥育猪复合预混合饲料≤40mg／kg。在饲料加工时。应注重对饲料原料中铅的检测,尽量使用铅含量低的饲料原料。     

营养素可以解毒

因谷物发霉而导致的经济损失,往往超过人们的预料,更为遗憾的是目前尚无理想的方法避免这种损失。可是某些特定毒物在机体中的代谢和毒性机理已为有关学者研究明白,并探索出了相应的有效对策。例如赭曲霉素A与转移核糖核酸(TRNA)结合后会妨碍蛋白质的合成,而苯基丙氨酸可以抑制这种有害的结合。因此,适量投予苯基丙氨酸便能减少乃至消除赭曲霉素A的毒性。另外,营养素也具有解毒作用。例如雏鸡饲料中维生素B_2的含量分别为3.0和6.7mg/kg的情况下,无铅时两种饲料对雏鸡的增重没有差异;饲料中加铅则6.7mg/kg组的增重明显优于3.0mg/kg组。试验还表明,饲料中营养素低于要求量时,有害物质及其毒     

铅在猪不同组织和器官中的富集状态

本试验旨在研究饲料中铅含量与猪组织和器官中铅含量的关系,及铅在猪各组织和器官中的分布规律,为制定猪可食用器官中铅含量限量标准提供理论依据.将24头大约克夏仔猪随机分为4组,分别饲喂含铅量为0.398mg/kg(对照组),6.095 mg/kg(低剂量组),17.49 mg/kg(中剂量组),51.674 mg/kg(高剂量组)的饲料,持续喂养90 d,屠宰、取其心脏、肝脏、脾脏、肺脏、肾脏、小肠、猪毛、猪皮、脂肪、猪血、骨髓、猪耳、猪舌、猪尾、里脊、臀尖、小排、后腿内,测定其中的铅含量.结果表明,随着饲料中铅含量的增加,猪体内各组织和器官中的铅含量均有不同程度的升高.对照组组织和器官中铅含量由高到低的次序为肾脏>脾脏>肝脏>毛发>其他组织和器官,其中肾脏、脾脏铅含量超标;3个给铅组组织和器官中铅含量由高到低的次序为骨髓>肾脏>脾脏>肝脏>毛发>猪尾>其他组织和器官;其中肾脏、脾脏、肝脏、猪尾均超标,但各组猪的肌肉、脂肪、猪皮、小肠等组织或器官中的铅含量较低,均符合国家标准<食品中污染物限量,GB 2762-2005>.表明随着饲料中铅含量的增加,猪组织和器官中铅的富集有所不同,其中骨髓、肝脏、肾脏和脾脏中的铅含量较高,猪皮、肌肉、脂肪、小肠、猪舌、猪心、猪肺等可食用组织和器官中铅的含量较低.     

饲料镉对罗非鱼的急性毒性及其安全限量的研究

为研究饲料镉对罗非鱼的急性毒性及其在饲料中的安全限量,将180尾罗非鱼随机分为6组,投喂镉含量分别为0、0.10％、0.25％、0.50％、1.00％和2.00％的饲料,每组3个重复,每重复10尾鱼.记录96 h鱼的病死率及中毒症状,并计算96 h半致死量(LD50)和安全限量.结果表明:罗非鱼饲料镉急性中毒症状与水环境中重金属致鱼中毒症状类似;饲料镉对罗非鱼的96h LD50为(49.67±6.11) mg/kg体质量(BW),安全限量为0.47 mg/kg.     

伊犁地区肉牛产业链中土壤、饲料及牛肉中重金属残留分析

为了解新疆伊犁地区肉牛产业链中重金素元素的残留情况,本研究采用原子吸收法对新疆伊犁地区肉牛养殖场的土壤、饲料及屠宰场的牛肉进行重金属砷、铅、汞、铬、镉的检测。结果表明土壤样品中重金属铅、砷、汞、铬、镉元素含量分别为0.03~0.20、3.87~8.30、0.15~0.23、0.09~0.48和0.41~0.86 mg/kg。饲料样品中铅、砷、汞、铬、镉元素含量分别为3.01~18.09、75.35~94.27、19.65~24.37、0.06~1.04和1.81~8.46 μg/kg。牛肉中铅、砷、汞、铬、镉元素含量分别为0.23~0.54、1.22~7.12、0.28~0.53、0.01~0.27及0.02~0.03 μg/kg。土壤和饲料、饲料和牛肉、土壤和牛肉中重金素含量的相关系数分别是0.96、0.99、0.98。综上所述,伊犁地区肉牛养殖场的土壤和饲料,屠宰场的牛肉中重金素铅、砷、汞、铬、镉元素的含量均没有超标,三者中重金属含量具有较高的相关性。     

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。     

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。     

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.