This "Book of Abstracts" represents the main publication of the 50th annual meeting of the European Association for Animal Production in Zurich, Switzerland, from 22-26 August 1999. It contains abstracts of the invited papers and contributed presentations including posters. The meeting and sessions in the field of animal genetics, animal management and health, animal nutrition, animal physiology, cattle production, horse production, pig production and sheep and goat production. In total 1765 authors contributed to this publication, which resulted in 715 abstracts.