6 Perspectives on the global regulation of genetically modified livestock.

Abstract Historically, genetically engineered (GE), also known as genetically modified, livestock containing a transgenic recombinant DNA (rDNA) construct have been subject to mandatory regulatory evaluation and approval prior to commercialization. This genetically modified organism (GMO) regulatory pathway has proven to be an insurmountable hurdle for many would-be food animal developers, with only two approvals (Aquadvantage Salmon, GalSafe Pig) of rDNA animals for food use in the 40 years since GE livestock were first reported. However, the advent of gene editing (GnEd), resulted in many countries modernizing their biotechnology regulatory approaches. In 2015, Argentina became the first country to consider products produced using modern biotechnology but lacking a “novel combination of genetic material” as akin to those produced using conventional breeding. Since adopting this approach, there has been a marked uptick in Argentine regulatory submissions from local companies and public-sector researchers pursuing novel welfare, adaptability and disease-resistance traits in animals using GnEd. Several GnEd animal applications have been judged to be “non-GMO” in at least one country, including knockout pufferfish, flounder and sea bream in Japan; tilapia and cattle in Argentina; cattle, tilapia, and porcine reproductive and respiratory syndrome (PRRS) virus-resistant pigs in Brazil and Colombia. The United States Food and Drug Administration (FDA) regulates intentional genomic alterations (IGA) under the Food, Drug and Cosmetic Act, and evaluates the IGA as a drug. FDA finalized two Guidance for Industry (GFI #187A,B) documents in 2025, detailing their risk-based approach to the regulation of IGAs in animals. The first class of IGA in food animals is “Category 2” products that the FDA has determined pose minimal risk, and therefore there is no expectation that developers will submit a formal application for approval of these products. Rather, the FDA can exercise enforcement discretion, meaning that because the FDA has determined that the product risks are understood, mitigated, the product does not warrant regulatory intervention, i.e. require an approval prior to commercialization. The second is “Category 3” products for which the FDA will require a formal premarket approval using data requirements proportionate to the risk associated with the particular product. In 2022, the FDA exercised enforcement discretion on two low-risk, heat-tolerant (SLICK) cattle submitted by Acceligen. In 2025, the FDA formally approved the PRRS-virus resistant pig application submitted by Genus plc. Some countries, notably South Africa, plan to regulate all products of modern biotechnology as “GMOs” irrespective of the nature of the modification or the presence of novel DNA, and the situation in the European Union is evolving. The future of gene-edited livestock, and ultimately the type of products that are able to be commercialized will be shaped by the development of harmonized, fit-for-purpose, risk-based regulatory frameworks that foster innovation, support trade, and promote public acceptance.