Antibiotic In feed

The presence of antibiotic resistant intestinal organisms resulting from the use of antibiotics in feeds is well established (, 5, ). Wanatabe ] ) reported on the transferability of this trait and Anderson and Lewis ( ) showed the transfer of antibiotic resistance between species involving Salmonella typhimurium. 

Residual antibiotics. With the widespread use of antibiotics in feeds the occurrence of residuals in milk, meat and eggs becomes inevitable. These residuals result primarily from failure by the producer to adhere to adequate withdrawal periods following the use of the antibiotics. In a review by Katz ( ), residual antibiotics were found in all animal species marketed in 1976 - 1978. 

Livestock production. The growth promoting attributes of antibiotics in feeds reside in their antibacterial activity in the... 

Most of the research on antibiotics in feeds was from 1950 to 1960, and this led to many interesting findings that have largely been forgotten (, . The diseased conditions that existed on... 

These examples were inappropriate. Overuse of ampicillin in medical practice was discussed by Wescoe on p. 27 of the FDA s own National Advisory Food and Drug Committee Report, on January 24, 1977. Wescoe said (speaking of antibiotics in animal feeds), "I really find it difficult to understand how you believe a hazard exists for instance, relative to Neisseria gonorrheae, where the disease is practically all human, where it has been treated worldwide for many years by ampicillin. .. and then strain to say that maybe that is in part due to subtherapeutic doses of the antibiotic in feed." Dr. Wescoe chaired the committee. 

Consumer Reports, March 1985, warned against "licking your fingers while eating raw meat" and said that the findings by Holmberg "appear to pull the rug out from under" those who had claimed there was no link between antibiotics in feed and human disease. The "hundreds of thousands of cases" are not... 

Organic producers can take several nutrition-related steps to control problems related to health of their flocks, with the banning of routine medication, including the use of antibiotics, in feed. These can be summarized as follows, and readers are directed to veterinary publications for a more detailed outline of the appropriate procedures. 

Microbial resistance Microbial resistance to antibiotics in feeds is not harmful per se, but may create a public health hazard if the resistance interferes with the control of a given microorganism, especially a pathogen, in animals or humans ... 

Henry, W. R. "Proceedings of the Antibiotics Presentations to the U.S. Food and Drug Administration Task Force on the Use of Antibiotics in Feeds". Washington, D.C., 1970. 

Antibiotics in feeds (see Chapter 24) have been used in intensive livestock systems to restrict infections, but their routine administration is now prohibited or discouraged because of the danger of producing antibiotic-resistant organisms. 

Another example is the purification of a P-lactam antibiotic, where process-scale reversed-phase separations began to be used around 1983 when suitable, high pressure process-scale equipment became available. A reversed-phase microparticulate (55—105 p.m particle size) C g siUca column, with a mobile phase of aqueous methanol having 0.1 Af ammonium phosphate at pH 5.3, was able to fractionate out impurities not readily removed by hquid—hquid extraction (37). Optimization of the separation resulted in recovery of product at 93% purity and 95% yield. This type of separation differs markedly from protein purification in feed concentration ( i 50 200 g/L for cefonicid vs 1 to 10 g/L for protein), molecular weight of impurities (<5000 compared to 10,000—100,000 for proteins), and throughputs ( i l-2 mg/(g stationary phasemin) compared to 0.01—0.1 mg/(gmin) for proteins). 

The nutrient sparing effect of antibiotics may result from reduction or elimination of bacteria competing for consumed and available nutrients. It is also recognized that certain bacteria synthesize vitamins (qv), amino acids (qv), or proteins that may be utilized by the host animal. Support of this mode of action is found in the observed nutritional interactions with subtherapeutic use of antibiotics in animal feeds. Protein concentration and digestibiHty, and amino acid composition of consumed proteins may all influence the magnitude of response to feeding antibiotics. Positive effects appear to be largest... 

Treponema hjoepsenteriae a causative agent of swine dysentery, is sensitive to polyether antibiotics at low concentrations in vitro. In pigs, lasalocid was effective in controlling dysentery at levels of 0.005—0.05% in feeds (167). Several species of Mycoplasma are inhibited in vitro at a MIC range of 2.0—25 p./mL of polyethers including narasin, cartiomycin, and K41 (164). 

Table 3 Hsts the polyether antibiotics used as poultry anticoccidial dmgs in the United States. Recendy, lasalocid and monensin have been approved for use in bovine coccidiosis at levels in feed of 11—33 g/t.

Choct M. (2001). Alternatives to in-feed antibiotics in monogastric animal industry . ATS Technical Bulletin, 30, 1-6. 

Collinder E., Berge G.N., Cardona M.E., Norin E., Stern S. and Midtvedt, T. (2000). Feed additives to piglets, probiotics or antibiotics , in Proceedings of the 16th International Pig Veterinary Society Congress, Melbourne, Australia. 17-20 Sept. 2000, pp 257. 

Inborr J. (2000). Swedish poultry production without in-feed antibiotics - a testing ground or a model for the future . Austral Poult Scie Sympm, 12, 1-9. 

Supervisory process control, 20 668 Supplemental antibiotics, in ruminant feeds, 10 870... 

This book was developed to provide a current perspective on agricultural use of antibiotics. Topics include some major uses of antibiotics, problems associated with their use from a regulatory standpoint, residues in food including methods of detection, risks to human health from use in feeds, trends in use, and overall risks and benefits. The scope, therefore, is much broader than in several other recent symposia that have focused mainly on the controversy regarding the use of antibiotics as feed additives. Many of the topics included in the present volume have not been discussed under one cover before. 

The practice of incorporating low levels of antibiotics in livestock feeds to promote growth has been particularly controversial. It is feared that this practice will result in development of resistant bacteria in animals, which will in turn be passed on to humans, thus diminishing the effectiveness of antibiotics in treatment of human disease. A petition from the Natural Resources Defense Council to ban such uses of penicillin and tetracyclines recently was denied by the Secretary of Health and Human Services. The controversy therefore is likely to continue. Opinion on the subject is quite polarized, and several points of view are presented in this book. 

Antibiotics in Animal Feeds Council for Agricultural Science and Technology, Report No. 88, March 1981. 

The advisability of using certain antibiotics, particularly penicillin and tetracycline, in animal feeds has been questioned because of their use in human medicine. Any use of an antibiotic that is prescribed for humans presents some risks to human health, whether the use is for humans, animals or for other purposes but. the uses also have benefits. Otherwise, they would not persist. Antibiotics are used in animal feeds to increase animal weight, increase efficiency of feed utilization, increase reproductive efficiency and decrease morbidity and mortality. These benefits to animals and animal producers are reflected in decreases in food costs to humans. There are also benefits to human health from use of antibiotics in food animals. By reducing the incidence of animal health problems, use of antibiotics in food animals reduce the transference of animal infections to humans. The contention that the effectiveness of penicillin and tetracycline for use in human medicine is rapidly diminishing as a result of the proliferation of resistant bacteria caused by subtherapeutic use of antibiotics in animal production is not supported by experimental data. Rather, the evidence suggests that a fairly stable level of resistance of the intestinal bacteria in humans has long since been established to penicillin and tetracycline as it has been in animals. 

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