Naturally, chickens live long. But in order for them to live longer, they have to be taken cared properly, with a quality of food, care and environment. Their coop must be designed for them to be well protected from dangers of bad weather and predators. As they are susceptible to sickness, they must be given proper nutrition. It is common for backyard chickens to live 8 to 10 years. Yet if they make it through all the dangers in life, they can live even up to 20 years.
Chickens are not actually designed to live long. Depending on your intentions why you raised them, will tell you how long they can live. They are naturally bred for meat and eggs. If their purpose is for meat, they are slaughtered before they mature, between 8 to 14 weeks old, for a quality meat. If the intention of the chicken owner is for them to lay eggs, they can be kept alive between 1 to 2 years old. Though they can live longer than 2 years but as they get older, the fewer eggs they produce. But, you must as well consider the other benefits you get from chicken aside from meat and eggs. They eat ticks, mosquitoes, flies and most of all, a source of fertilizer.
Some chickens are kept longer for breeding purposes. But not for a very long time since their body is designed to put on weight quickly and their bones and hearts cannot handle strain. If they live past 3 years, they will oftentimes have health issues and they stop laying eggs. It is not rare that you find a dead chicken in your coop. It happened once in a while with no specific reason and warning symptoms. This is what is called “sudden chicken death”. They just simply give out.