Registration of herd treatments and concerns related to increasing bacteriological resistance characterised the changes to Danish legislation during the 1990s. In 2000, the introduction of a total antibiotic growth promoter ban led to an increase in diarrhoea related problems, often caused by infections with haemolytic E.coli and Lawonia intracellularis. Some weapons against the gastrointestinal diseases have been found and producers are warned to be prepared.