Impact of strategies to reduce antimicrobials in livestock, including aquaculture, under field conditions: a structured scoping literature review

Antimicrobials are extensively used in livestock and aquaculture, exacerbating the antimicrobial resistance pandemic. A lack of knowledge about alternatives to replace antimicrobials, and their effectiveness, hampers changes in farming practices. This work aimed to understand the impact of strategies to reduce antimicrobial usage in livestock, including aquaculture, under field conditions, using a structured scoping literature review. The PRISMA-ScR guidelines were followed and the PICOTS framework used. Articles were identified from Cab Abstracts, Medline and Scopus. A total of 7,505 articles were screened; 203 of which were included in the review. Given heterogeneity across articles in the way strategies were described, a qualitative synthesis was conducted. There were differences in the impacts of the strategies between and within species. Some options seem more promising than others, as their impacts were consistently equivalent or positive when compared to animal performance using antimicrobials.  This work provides a data to address the identified data gaps.