A classic small‑scale poultry scene: a hen in a simple wooden coop, with a group of young chicks exploring the ground around her. The enclosure is basic—wooden panels, a nesting box, and wire mesh—exactly the kind of setup found in backyard or hobby poultry keeping rather than in commercial production.

Backyard farming refers to small‑scale, non‑commercial poultry keeping undertaken at household level, typically involving simple, improvised housing, mixed‑age flocks, and minimal mechanisation. Birds are frequently reared under natural conditions, with broody hens providing incubation and early chick care, and with direct access to soil, vegetation, and the wider outdoor environment. Whilst such systems are culturally valued and contribute to household food security, they operate with limited biosecurity, irregular hygiene routines, and unrestricted contact with wild birds and other domestic species. Consequently, backyard flocks function as heterogeneous and largely unmonitored reservoirs of infectious agents, including respiratory pathogens such as Newcastle disease or avian influenza, enteric parasites, and environmentally persistent organisms. Their proximity to commercial farms and the movement of people, equipment, and fomites between sectors create a continuous interface through which pathogens may be maintained, amplified, and reintroduced into the commercial poultry population. For these reasons, backyard farming represents an epidemiologically significant component of the wider poultry ecosystem, despite its modest scale.