Antibiotic growth promoters for the view of animal nutrition

From 01. 07./09. 1999 on six further antibiotic growth promoters have been banned--with only four substances remaining in this group of feed additives. Therefore, the discussion on a possible induction of bacterial resistance by antibiotic growth promoters, especially in potentially pathogenic bacteria, will sooner or later come to an end which is not least in the interest of the reputation of animal husbandry and food of animal origin. Unfortunately, no short-term solution for health problems by legislation--especially in the gastrointestinal tract--during rearing and the beginning of the fattening period is possible as experiences in Sweden have distinctively shown. Anyway, growth promoting feed additives were not a cure-all of rearing problems, in spite of their use considerable amounts of antibiotics were prescribed during this period. But growth promoters (especially chinoxalines) were most suitable for the prophylaxis of a microbial imbalance in the gastrointestinal tract. Therefore, after the ban of these effective representatives of feed additives the amount of prescribed antimicrobial drugs for metaphylaxis and therapy should be critically observed. The questions of practicable alternatives will be primarily addressed to the fields of animal nutrition, veterinary medicine and feed industry. To answer these questions and to evolve new solutions (as well as to check their suitability in practice) is considerably more intricate than simply to ban these substances which is more attractive for the media, however. It is no progressive solution to give up antimicrobial growth promoters as feed additives and to use the same substances (for example olaquindox) as therapeutics now (prescribed by veterinarians) or to switch to zincoxide or copper (in a dosage high above all nutrient requirements) in order to prevent postweaning problems due to E. coli. But one has to take into consideration the reasons for the use of antibiotics (growth promoters and therapeutics) or other "aids" (e.g. ZnO, Cu) in food producing animals (especially in beef-cattle, pigs and poultry) in "modern" production systems. The matter for conflict is the contrast between a minimised use of antimicrobial substances, as science as well as general public demand, and the requirements of "modern" livestock industry (rationalisation, increase in performance, specialisation, concentration) and general economy (save of resources, lowering of production costs). These well-known and expected problems arise in an almost exemplary manner in the case of antibiotic growth promoting feed additives. Therefore it is most difficult to impart suggestions to the persons involved as well as to the public.