This publication contains the proceedings of a seminar held in Germany (Fed. Rep.) on May 4 -6 1977 under the auspices of the Commission of the European Communities as part of the EEC programme of co- ordination of research on beef production. The programme was drawn up by a combined scientific working group on Genetics and Selection and on Nutrition and Management on behalf of the Beef Production Committee. The working group consisted of Professor Dr. Neimann- S rensen (Denmark Chairman) Dr. Brolund Larsen (Denmark) Mr. Boccard (France) Dr. H. de Boer (Netherlands) Priv.-Doz. Dr. B. Hoffmann (Germany Fed. Rep.) Professor Dr. H.J. Langholz (Germany Fed. Rep.) Dr. J.W.B. King (UK) Mr. R. Jarrige (France) Mr. B. Vissac (France) Professor Dr. A. Romita (Italy) Professor Dr. E.P. Cunningham (Ireland) Mr. P. L Hermite (CEC) and Dr. J.C. Tayler (Scientific Adviser to CEC). The subject chosen for this seminar was drawn from the list of priorities in research objectives drawn up in 1973 by members of a committee (now the Standing Committee on Agricultural Research ( PRA). One of the functions of this series of seminars was to summarise and update the information available on the selected subjects and to discuss future needs for research so as to assist the Commission in evaluating the probable impact of research on agri- cultural production within the Community.