Why do humans keep animals? Does the answer help to define standards for organic animal husbandry?

Summary

Domestic livestock, such as farm animals and pets, are part of the cultural heritage of mankind. Animals have been used for food, services, non-food or religious purposes or just as a hobby for thousands of years. Man-made breeding has created livestock that are adapted for different purposes and functions.
Today, thousand of breeds exist: adapted to the various conditions in human households.
The discussion of animal welfare and the definition of standards for livestock keeping have to consider the different functions, ethical values and perceptions of people involved (Badura, 1999). The differences of culture, as well as private and common wealth between individuals, regions and countries, can be a reason for different standards for animal keeping. This discussion can become easier with an understanding of the functions of animals from a historical and ethical perspective. This can help to answer the question of how the animals should be kept.