[Some ethological features in farm animals (author's transl)].

A number of general ethological principles are discussed in the present paper. Attention is paid to normal and ritualized behaviour of cattle and swine during mating and on aggression. The fact is stressed that external stimuli during the period of so-called imprinting may also affect the future behaviour of cattle and swine. This is of particular importance in male animals used in artificial insemination. Finally, the effect of social stress on symptoms such as cannibalism, gastric ulcers and avian hysteria is discussed.