Trained immunity in farm animals.

The mechanisms that enable the innate defence system to "remember its enemies" have opened a new field in immunology, and the evolutionary links among the various defence mechanisms are now being uncovered. In humans, advances in trained immunity have improved our understanding of host-pathogen interactions and broadened the search for new vaccines and treatments as alternatives to antimicrobial drugs. Similarly, veterinary medicine continues to seek strategies to safeguard animal safety, health, and welfare. Animal protein is obtained from meat, milk, or its derivatives, and eggs. Farms play a crucial economic and ecological role, and are a priority for ensuring global food security. The main farm animals used to obtain protein are cattle, sheep, goats, pigs, poultry, fish, and shrimp. Understanding the mechanisms underlying trained immunity in these intensive production systems will deepen our knowledge of host-pathogen interactions and support the development of more effective disease control strategies. It is therefore essential to ensure animal productivity, health, and well-being, as well as to minimise the environmental impact of these intensive production systems through more sustainable practices. This review examines advances in trained and primed immunity in farm animals and discusses the future of trained immunity in the farming sector.