The aim of this study was to indicate why the use of colistin has increased in the pig (and poultry) sector over the last few years (since 2017), and what steps can be taken to reduce the use of colistin in the relevant sectors. Colistin is regarded by the WHO as a highly prioritized critically important antibiotic for human medicine. As a result, the use of colistin in veterinary medicine has been under pressure in the pig (and poultry) sector. In order to study the use of colistin, two Veterinary Antimicrobial Stewardship teams (A-teams) were formed, consisting of a total of eight pig veterinarians. In the Netherlands, the highest colistin use occurs in weaned piglets, the main cause of which is 'postweaning diarrhoea'. The study did not identify any clear causes for the gradual increase of colistin use after 2017, but the A-team participants suggested there could be a connection with the ban on zinc oxide and a mismatch in feeding management. The A-team participants suggested necessary preconditions for a good weaning process and optimal feed management to ensure the health of newly weaned piglets. In addition to these preconditions, the veterinarians identified two factors that are important for the prevention of postweaning diarrhoea: weaning age/management and feeding management. Although the use of A-teams has not explicitly led to a reduction in colistin use (mainly because the participating veterinarians were already low prescribers), the participants indicated that the A-team is a valuable form of peer group reflection where colleagues from other practices can talk about antibiotic prescribing behavior.