兽药和饲料添加剂残留的毒性与生态毒理研究进展

兽药残留包括兽药在动物性食品中的残留和在生态环境中的残留。前者对消费者造成直接的危害，主要表现在：直接的毒性作用，对人类胃肠道菌丛的影响和使病原菌耐药菌株增加。在环境中的生态毒理包括对土壤生物群落的影响，对水生生物的影响，对昆虫的影响和在环境中的转归。文章阐明兽药残留与人类健康和生态环境有十分密切的关系，对其进一步深入研究有重要的理论与实际意义。

规模养殖场兽药和饲料添加剂残留的对策

近几年来,随着畜禽规模养殖场的迅速发展和现代规模化、集约化畜牧业的快速发展,兽药的应用品种和饲料添加剂的使用数量也在不断增加,兽药和饲料添加剂残留作为动物源性食品安全性影响的重要因素,已受到社会的普遍关注,并成为各种新闻媒体争先报道的一个热点问题。兽药残留不仅直接对人体产生急性、慢性及毒性作用,引起细菌耐药性的增加,而且还通过环境和食物链的作用间接对人体健康造成潜在危害,直接影响我国养殖业的发展和畜禽产品的出口创汇。因此,必须采取坚决果断的有力措施,减少和控制兽药和饲料添加剂残留的发生,而如何控制兽药(饲料添加剂)的残留?结合当前无公害畜产品认证工作的实际,浅谈一下笔者对控制药残的几点体会。

中国稻渔种养系统水稻产量差及影响因素的整合分析

为了揭示稻渔种养系统生产潜力和制定高产高效栽培措施提供科学依据。从中国知网和web of science等2个数据库,分别以稻渔(包括稻虾、稻鱼、稻蟹、稻鳖、稻鳅)、施肥、产量、种植密度、种植方式、rice-fish、rice-crayfish、rice-crab、rice-turtle、rice-loach、yield、variety、seeding density、planting pattern、fertilizer and China等为关键词检索,共收集目标文献108篇。总结稻渔系统水稻的产量潜力和产量差,通过分析品种、施肥量、种植密度、种植方式和饲料氮磷残留对稻渔系统水稻产量的影响,阐明稻渔种养系统水稻产量差的影响因素及缩小产量差的途径。结果表明,当前我国稻渔系统产量潜力较大,稻虾、稻鱼、稻蟹、稻鳖、稻鳅模式水稻高产纪录分别为9.64、9.46、10.47、9.14、9.62 t/hm^(2),总样本平均产量分别实现了潜力产量的79%、75%、76%、74%、78%,其中水稻品种、种植密度和施肥量是产量差的主要限制因素。稻虾模式氮磷钾最优施肥量分别为86.2、69.2、66.5 kg/hm^(2),稻鱼模式分别为151.3、45.7、108.0 kg/hm^(2);杂交稻的稻虾、稻鱼、稻鳖和稻鳅模式水稻产量比常规稻增加3.9%~50.6%;籼稻产量在稻虾、稻鱼、稻鳖和稻鳅模式下比粳稻增加4.6%~25.6%。稻虾、稻鱼、稻蟹和稻鳅系统水稻的适宜种植密度分别为32.2万、30.2万、24.7万、45.1万株/hm^(2);另外,一定量饲料氮磷残留可提高水稻产量。我国稻虾、稻鱼、稻蟹、稻鳖、稻鳅模式下水稻的增产潜力分别为2.07、2.39、2.50、2.37、2.15 t/hm^(2)。适宜的品种、施肥量、播种密度和饲料氮磷残留量可以缩小产量差,其中品种以籼稻和杂交稻为宜;优化施肥量可以使稻虾和稻鱼模式下水稻分别增产5.5%、5.1%;优化种植密度则使水稻增产4.8%~15.5%。

Effect of Dietary Olaquindox on the Growth of Large Yellow Croaker(Pseudosciaena crocea R.) and the Distribution of Its Residues in Fish Tissues

Olaquindox(OLA), one of quinoxaline-N, N-dioxides, has been put under ban. However it was used as a medicinal feed additive early; it promotes the growth of livestock and prevents them from dysentery and bacterial enteritis. In this study, we evaluated the effect of dietary OLA on the growth of large yellow croaker(Pseudosciaena crocea R.) and the histological distribution of OLA and its metabolite 3-methyl-quinoxaline-2-carboxylic acid(MQCA) in fish tissues. Four diets containing 0(control), 42.5, 89.5 and 277.2 mg kg-1 OLA, respectively, were formulated and tested, 3 cages(1.0 m × 1.0 m × 1.5 m) each diet and 100 juveniles(9.75 ± 0.35 g) each cage. The fish were fed to satiation twice a day at 05:00 am and 17:00 pm for 8 weeks. The survival rate of fish fed the diet containing 42.5 and 89.5 mg kg-1 OLA was significantly higher than that of fish fed the diet containing 0 and 277.2 mg kg-1 OLA(P < 0.05), while the weight gain rate of fish fed the diet containing 42.5 and 89.5 mg kg-1 OLA was significantly higher than that of fish fed the diet without OLA(control)(P<0.05), but similar to that of fish fed the diet with 277.2 mg kg-1 OLA. Fish fed the diet with 277.2 mg kg-1 OLA had the highest content of OLA and MQCA in liver(3.44 and 0.39 mg kg-1, respectively), skin(0.46 and 0.09 mg kg-1, respectively) and muscle(0.24 and 0.06 mg kg-1, respectively). In average, fish fed the diet containing OLA had the highest content of OLA and MQCA in liver which was followed by skin and muscle(P < 0.05), whereas OLA and MQCA were not detectable in control. Our findings demonstrated that OLA and MQCA accumulated in large yellow croaker when it was fed with the diet containing OLA, thus imposing a potential safety risk to human health.

共筑畜产品安全堡垒

在进入新世纪的今天，食品安全已为全球关注，而畜产品安全更是重要话题。5月18日，本刊借第三届全国畜牧业暨饲料工业交易会召开之际，邀请部分国内兽药、饲料、生物工程开发及种猪育种等方面的企业代表，在大连华日大酒店举行了“畜产品安全问题”研讨会。参会的企业技术专家着重就“畜产品安全”展开了深入探讨。