【作者】 徐震宇；

【导师】 刘建新；

【作者基本信息】 浙江大学 ， 动物营养与饲料科学， 2003， 硕士

【摘要】 本研究在综述了影响动物源食品安全性的潜在饲粮因素的基础上，着重研究了当前危害最严重的盐酸克仑特罗(Clenbuterol-HCL)在猪体内的消长动态(试验1)，监测了宁波市1999—2002年盐酸克仑特罗残留情况(试验2)，提出了实施饲料安全的对策措施。 大量的文献资料表明，动物饲料和饲草中大部分的污染物和毒物来源于人为和自然因素。一些化学和生物成份被有意或无意地加入到饲料中去，可使动物源性食品产生有毒有害物质，并且这些成份可能进入饲料饲喂前的任何阶段。根据来源，饲料中的有毒有害物质可以分为四种：(1)天然的有毒有害物质，如蛋白酶抑制剂，生物碱等；(2)次生的有毒有害代谢物，如霉菌和亚硝酸盐；(3)化学性和生物性污染物；(4)人为添加物质，包括微量元素和违禁兽药，如β—兴奋剂。现阶段影响我国饲料安全的因素包括人为加入和饲料加工过程中产生的化学物质、微生物、低利用率饲料及饲料原料的污染，其中危害最严重的包括霉菌毒素、违禁药物、重金属、兽药、农药等。近几年来，盐酸克仑特罗的违法使用引起国人的广泛关注，本文重点就该药物进行了相关的试验研究。 试验1，本试验分成二个阶段，第一阶段，利用3种不同浓度的盐酸克仑特罗饲喂育肥猪，收集不同时期的尿液；第二阶段，育肥猪停止饲喂盐酸克仑特罗后，采集不同时期的尿液和宰后肝脏。采用酶联免疫吸附测定法(ELISA)，测定了尿液和肝脏中的盐酸克仑特罗残留含量，探讨了其在猪体内的消长动态规律。结果发现，饲喂不同浓度的盐酸克仑特罗，其残留在猪尿液中达到峰值的时间相同，一般只需要4-6小时即可，而且峰值随添加剂量值的增大而升高。消除速度比吸收速度缓慢，不同浓度盐酸克仑特罗在尿液中的消除时间一般都在10天以上，而且随体内浓度的增加，消除时间随之延长。盐酸克仑特罗在肝脏中的残留时间比尿液中更长，在不同浓度使用15天后均可检出，高浓度用量时在25天后仍可检出。 试验2，在1999-2002年，在集贸市场、生猪定点屠宰场、猪场及饲料生产企浙江大学硕一卜学位论文业进行定期随机抽取相关样品计2 766份，采用ELISA、气相一质谱联用法(GC/MS)检测样品的盐酸克仑特罗残留，并按不同年份、区域、猪的来源、采样场所及猪体部位等进行了分析。结果表明，宁波市盐酸克仑特罗阳性检出率按年度呈现一定的变化，到2002年呈非常显著下降，不同区域的变化趋势与全市总趋势相同。宁波市外运入猪的盐酸克仑特罗阳性检出率明显高于本地猪。按猪体不同部位的情况看，盐酸克仑特罗阳性检出率以猪毛为最高(30.8%)，含量则以猪尿中为最高(270.3ng/m1);猪肉与其他可食组织中盐酸克仑特罗残留检出率为10.5% (14/1 34)，含量以猪肺为最高，肝、肾次之，猪肉中最低。 这些结果说明，完善相关法律、为了保证人们消费的动物性食品的安全性，我国政府部门制订了许多法规，并使这些法规得到了严格的执行。比如发布一系列的标准、规范和法律来管理和实施饲料、饲料添加剂和兽药的标准化;合理控制生产和使用兽药和农药;同时，建立残留监测体系。所有这些，都需要涉及饲料和动物产品的诸多方面的合作，以确保安全的畜牧业生产。本文建议动物饲料生产者应该在执行良好生产规范(GMP)的基础上，建立质量保证体系和运用危害分析和关键控制点(HACCP)管理体系。更多还原

【Abstract】 Literature review was firstly conducted to clarify the dietary factors affecting the safety of foods of animal origin. Two experiments were designed: (1) to study the dynamic of Clenbuterol-HCL (CL) in body of pigs by determining its residues in urine at different times while being continuously added or after cease of adding (Expt.l), and (2) to investigate the occurrence of CL from 1999 to 2002 in City of Ningbo, Zhejiang Province (Expt.2).From large number of literature, it is indicated that animal feeds and forages contain a wide range of contaminants and toxins arising from anthropogenic and natural sources. Certain chemical substances and biological agents incorporated into feed, either intentionally or unintentionally, can result in hazards in food of animal origin, and may enter feed at any stage of production up to the point of feeding. In terms of the sources, the feedborne hazards may be classified into four categories: (a) hazards inherent in feeds such as protease inhibitors and lectins; (b) secondary metabolites such as mycotoxins and nitrite; (c) contaminants including chemicals and infectious agents; and (d) artificially adding substances including micro-minerals and even contraband veterinary medicines and chemicals such as p-agonists. In current Chinese situation, the main factors affecting safety of animal feed include chemical agents, drug and microbeadded or/and produced while processing, among which mycotoxins, contraband veterinary medicines and excessive heavy metals, agricultural chemicals are most serious. In this paper, CL was mainly dealt with in two experiments.Forty eight growing-finishing pigs (hybrid from Duroc x Landrace x Large White) weighing 60 kg were used in Expt. 1 that was divided into two stages. At the first stage, samples of urine were collected at different intervals during 10 days from four groups of pigs that were continuously added CL at levels of 0, 1, 2 or 5 ng/kg diet. And the CL was withdrawn from the diet and Expt. 1 entered into Stage two. The samples of urine were then collected at days 1, 2, 6, 9, 12 and 15. In both stages, samples were collected triplicate from each animal for each time of collection. On the 15th and 25th days post-administration, two pigs were slaughtered from each group and samples of livers were collected. Concentrations of CL were determined in all samples of urine and livers by Enzyme-Linked Immunosorbent Assay (ELISA). Concentrations of CL in urine of pigs reached the peak at about 4 hours after feeding irrespective of the adding level, while the peak values varied for different levels and increased with adding level of HCL. The elimination of CL in urine was slow. Its occurrence in urine lasted for more than 10 d, longer with the increasing addition level. The residual time of CL in livers was longer than in urine, usually longer than 15 days, but its residue was found even after more than 25 days when the pigs were fed on diet with high level of CL.Experiment 2 was carried out to investigate the change in occurrence of CL in City of Ningbo during 1999-2000 depending on year, region, locale and source and parts of pigs and spatial distribution. A total of 2 766 samples including urines, hairs, meat and visceral organs of pigs were randomly collected from pig farms (2 455), fixed slaughterhouse (147), farm markets (134) and feed manufacturers (30) by stages and batches during March 1999 to March 2002 and were detected for the residue of CL by ELISA and GC/MS. The occurrence of CL-positive samples was the highest in 2001 (30.7%) and sharply dropped to 8.0 % in 2002, apparently resulting from the standardization of the relevant laws and codes and attention to safety of feed by farmers.Concentration of CL in the positive samples ranged from 1.0 to 270.3 ppb, and was less than 5 ppb in 83.49% of sample (435/521). There existed differences in occurrence of CL between different regions of Ningbo, the yearly variability was similar to the average. The occurrence of CL was obviously higher in the imported pigs (37.4%) f更多还原