Cattle heat stress in Australian beef systems is conventionally framed as a management problem requiring infrastructure solutions—shade cloth, sprinklers, fans. This paper reframes heat stress as ecological mismatch: European cattle (Bos taurus) operating outside the thermal, structural, and behavioural envelope in which their endocrine, immune, and reproductive systems evolved. Under this framework, cortisol elevation is not a transient 'stress response' but a persistent compensatory state; productivity loss represents biological reallocation toward survival; and shade is not infrastructure but missing habitat structure. We compare two intervention paths: (A) adapting the species to degraded ecology through genetic selection and mechanical compensation, versus (B) restoring ecology for the species through silvopasture integration. Path A creates dependency and narrows genetic potential; Path B enables compounding returns across productivity, carbon, biodiversity, and animal welfare. The analysis extends the Collaborative Homeostasis framework—previously applied to koalas, Tasmanian devils, coral, and dolphins—demonstrating that the same stress→dysregulation→disease grammar operates across managed biological systems.