Each use of antibiotics can lead to the selection of resistant bacteria. When animals are treated with antibiotics, there is the risk of spreading resistant bacteria from animals to humans. One of the main areas of use of antibiotics in livestock husbandry is the control of diarrhoea in weaned piglets that have been separated from the mother sow and her milk. The use of plant-based active substances such as tannins or essential oils in diarrhoea prevention is meant to reduce the use of antibiotics in pig production. This in turn could mitigate the problem of resistance development. The possible spread of resistances via the pipes of liquid feeding systems on pig farms is also being investigated with the aim of formulating concrete recommendations for farmers.