生长促进剂GROWTH STIMULANT / PROMOTER生长促进剂应用研究进展The development of growth stimulating substances张桂国博士山东农业大学动科科技学院Department of Animal Science and Technology2011/5/51 概要Introductionz为获取更多的动物性食品，人们一直在努力研究如何搭配已知营养素，同时寻求新的饲料添加剂来促进动物生产、提高生产效率。
–The constant effort to produce human foods from animal sources more efficiently and at lower cost to the consumer has stimulated continued search for more suitable combinations of known nutrients and for newadditives which will increase the efficiency and rate of growth and thelevel of production of animals.2 定义和分类Definition & varieties/ classificationz定义：提高畜禽、水产动物生长速度的饲料添加剂。
–起源：最早应用的促生长剂是抗生素。
Moore and associates (1946) Wisconsin UniversityStokstad and Jukes (1949) University of FloridaMcGinnis and associations Washington state university chicks Yang pigs金霉素chlortetracycline链霉素z分类：–抗生素，砷制剂，激素类（促生长）；–抗菌、抗霉、驱虫剂;–酶、益生素…….–Antibiotics, arsenicals, and hormonal compounds (growth stimulants); –Antimycotics, antiprotozoals, and pesticides (disease prevention treatment).–Enzymes, probiotics…….抗生素Antibioticsz抗生素：抵抗(破环)生命的物质。
–是由一种微生物合成的复合物，能特异性抑制另外一种或几种微生物，也包括用化学合成或半合成法生产的具有相同或相似结构或结构不同但功效相同的物质。
–Antibiotic means against life, or destructive of life.An antibiotic is a compound synthesized by a living organism which inhibits the growth of another or several kinds of other organisms.It also includes thosesubstances that, synthesized by chemical methods, have the same orsimilar structure , but have the same function in practice.发现历史the history of applicationz1928年到1940年英国伦敦圣玛利学院的细菌学家弗莱明-病理学家法劳来和化学家秦因(青霉素)z1946年Moore等发现抗生素在肉鸡饲料中添加有促生长作用z1969年Swann报告提出抗生素的耐药性z1974年欧盟决定禁用所有对肠道细菌和其他微生物有选择压力而产生抗药性的细菌z1999年禁用除黄、盐、莫、阿外的所有抗生素z1950年就得到美国饲料监督局（AFCO）和国家食品药物管理局（FDA）批准在饲料中添加抗生素z FDA明确规定药物的使用对象、时间、剂量等，要求2003年前完成对所有抗生素的重新评价z我国1987、1994、1997、2001年四次修订《饲料药物添加剂使用规范》产品有增有减抗生素研究阶段the stage for applicationz20世纪50-60年代饲用抗生素为人畜共用的药用抗生素（青霉素、链霉素、四环素、杆菌肽锌）；z60年代后-80年代意识到细菌的抗药性及抗生素残留性，饲用抗生素应与人用抗生素分开，开始研制专用饲用抗生素（forage antibiotic）z80年代-筛选研制无残留、无毒副作用、无抗药性的专用饲用抗生素，与人用抗生素及兽药分开。
分类classificationz 不同种类抗生素促生长效果–Growth responses to various antibiotics differed appreciably.促生长效果Growth responses of animal Relative growth responses of pigs fed various antibiotics 对照对照020406080100120140160index of growthindex of feed/grain V a l u e s 对照金霉素土霉素青霉素杆菌肽锌链霉素氯霉素粘多杆菌素新霉素枯草菌素Source: R. Brade The value of antibiotics in the nutrition of swine (1953)促生长效果Growth responses of animalz 不同抗生素促生长效果有较大差异–There have been important differences in the way various animals respond to antibiotics.–Calves show greater growth responses to chlortetracycline andoxytetracycline than to bacitracin, and growth depression occurred with penicillin .(Leonard A 1990)金霉素、土霉素杆菌肽青霉素>calvesz影响抗生素应用效果的因素The factors that influence the effectiveness of antibiotic–抗生素类别–饲粮类型：较低营养水平更显著Difference between control and treated animals are greater when the dietis slightly deficient or marginal in protein, B-vitamins, or certain mineralelements.–饲养条件：饲养管理条件越差效果越明显Pigs and poultry also show greater responses on poor diets than on highest quantity feeds.–动物种类、生长阶段：幼年动物比成年动物更有效50年代以来抗生素在猪饲养中应用效果（杨凤，2004）z抗生素做猪生长促进剂的效果（%） 阶段 指标使用抗生素后的改善程度 1950-19771978-19851990-1996断奶猪日增重16.11524.53饲料利用率 6.9 6.5 5.9生长育肥猪日增重4 3.69饲料利用率 2.1 2.4 3.6z断奶期的效果优于生长育肥期。
z对提高生长速度的效果优于改善饲料利用率的效果。
抗生素的其它作用other effects of feeding antibioticsz添加抗生素会增加动物采食量，降低料重比；z提高出栏整齐度。
–Animals that respond to antibiotic feeding usually consume more feed than controls and less feed isused per unit of weight gain.–Because there are fewer unthrifty animals, thegrowth rates are more uniform.抗生素的其他作用other effects of feeding antibiotics z有效添加剂量在不同动物从5～30g/T饲料不等–Effective levels vary from 5 to 30 g per ton of feed for the different animals and types of feedz高剂量抗生素（100-200g/T feed）在饲料中短期添加用于治疗已发生疾病。
–The use of high levels of antibiotics,100 to 200 g per ton of feed, for short periods for poultry flocks having certain chronic infections, suchas respiratory diseases, appear to stimulate recovery and bring the birdsback into efficient growth or egg production sooner than otherwisepossible.z过低剂量的抗生素（20-50mg/100kg of body weight）不能预防和治疗反刍动物蹄叶炎、乳房炎及其他感染。
–Low-level feeding of antibiotics is not an effective preventative or cure for foot rot, mastitis, or other specific infection.z药物添加剂的用量与作用效应的关系抗生素作用机制Mode of action of antibiotics1. 抑制或杀灭病原微生物，减少疾病发生。
2. 抑制肠道内有害微生物区系，维持肠道内微生物平衡。
3. 动物小肠肠道变薄，肠绒毛变长，提高养分吸收率。
4. 减少动物腹泻，尤其是幼龄动物，促进动物生长。
存在的问题some issuesz病原菌产生抗药性问题z抗生素在动物体内和产品中的残留问题瘦肉精的肉无皮下脂肪合理使用Proper usage of growth stimulantsz遵守相关国家法规z控制添加剂量z控制停药期–Drug withdrawal time, Drug elimination timez控制药残在规定范围内–To avoid the antibiotic residue合理使用Proper usage of growth stimulants z动物的抗药性来自于治疗用药而非饲料添加。