Regulations for the protection of useful animals can be traced to the early history of Law. The reason for such regulations has hardly changed up to the present: the expedient incorporation of the animal into the hierachy of values of the prevailing times. Decisive impulses invariably originated from the legal conception, the need for legal protection as well as from the scientific conceptions of society. The development rarely took a linear course and was not without setbacks. The prevention of cruelty to animals has always been faced with particular conflicting situations. Our pluralistic society with its marked philosophy of profit-making has to face such a problem, in particular as a result of livestock keeping in modern systems. The necessity and legitimacy of a permanent supply of large quantities of high-grade animal foodstuffs to be offered to our present industrial society on a competitive and low-cost basis, have contributed to this development. The public and parliament have for some time been demanding a modern federal act for the prevention of cruelty to animals based on a technical conception allowing also those questions of animal protection related to the present keeping of useful animals to be integrated, thus achieving a gradual balancing of interests. Such an Animal Protection Act came into force on October 1, 1972. On account of its scientific orientation it prompts us to give renewed thought to many present-day ideas about the keeping of animals, especially of useful animals, employing modern systems. With this objective in mind the Act has already strongly influenced the developing international harmonization of provisions for Animal Protection. The problems linked with "Animal Protection/Keeping of Useful Animals" require a harmonization of the ethical, scientific, economic and legal aspects as an indispensable prerequisite. On the basis of expert opinions prepared by a group of specialists of the Federal Ministry of Agriculture on the minimum requirements to be satisfied by modern systems of fowl breeding, the various scientific basic concepts and evaluations are presented. The value of the information yielded by modern research into animal behaviour is emphasized in this connection. Future legal ordinances in accordance with Clause 13, para 1 of the Animal Protection Act of July 24, 1972 for the protection of useful animals kept in modern systems call for a particularly thorough scientific foundation which must also stand up to examination by the courts. The problems to be solved require comprehensive research. An urgent task for the near future will be to give the resolution of these problems a firm scientific base. In addition to the topical approach to the subject "Animal Protection/Keeping of Useful Animals", indications are given for a comprehensive approach which will prove indispensable in the future...