[Prospects and limits of animal breeding from the physiological aspects]

Livestock breeding is characterized by substantial increases in performance in recent years. However, pathophysiological changes have to be considered when increased production levels will exceed maximal physiological capacities. Gastrointestinal adaptation processes of ruminants kept under aride grazing conditions are discussed in comparison with european sheep breeds. The high stress susceptibility in pigs which is genetically determined is taken as a further example to explain the onset of diseases on the basis of pathophysiological mechanisms being induced by breeding techniques. From this the necessity for a close cooperation between animal breeding and physiology has to be concluded.