Billions of farm animals are kept indoors, and oftentimes in tight cages, for the entirety of their lives. This unhealthy and unnatural way of confining animals is ultimately not healthy for humans. Such a confinement makes animals very susceptible to diseases by lowering their immune response. Human beings then consume meat and other products from animals that may not be the healthiest to begin with. Add to it the increased antibiotic and other medications that are needed for these animals. Those antibiotics can cause other very serious global problems, including the evolution of drug-resistant bacteria. 

Animals should be given mandatory outdoor free time where they can roam around and explore their surroundings. This can be as little as an average of an hour per day. Just like in human beings, outdoor activity will boost immunity in animals, resulting in healthier animals with fewer drugs in their system. Healthier animals mean healthier humans. A farmhouse that is empty of animals on a nearly daily basis for short durations has other advantages too, including the opportunity to perform regular full-scale cleaning and sanitization, further reducing the possibility of diseases.