No, there should not be a mandatory age of retirement. So long as a person is capable of working and producing good work, then his/her age should not matter. In addition, forcing everyone to retire at a certain age puts a strain on the economy of a nation as those individuals must be cared for.
People should be allowed to retire when they want to or when they need to. I don't think there should be a minimum age because some people would need to retire before that age and some would need to retire long after that age. Some people need to continue to work their entire lives in order to survive and it would be unfair to force retirement.