Professor Johan Greyling is Head of the Department of Animal, Welfare and Grassland Science at the University of the Free State, South Africa. He is also Editor-in-Chief of the journal Small Ruminant Research as well as Associate Editor of the South African Journal of Animal Science. He has published widely in the area of animal breeding and worked with major international organisations such as the International Livestock Research Institute (ILRI). Dr Julius van der Werf is Professor of Animal Breeding and Genetics at the University of New England, Australia. He is co-Editor in Chief of the journal Genetics, Selection, Evolution and Associate Editor of the Journal of Animal Breeding and Genetics. He is also member of the College of Experts of the Australian Research Council. Professor Johan Greyling is Head of the Department of Animal, Welfare and Grassland Science at the University of the Free State, South Africa. He is also Editor-in-Chief of the journal Small Ruminant Research as well as Associate Editor of the South African Journal of Animal Science. He has published widely in the area of animal breeding and worked with major international organisations such as the International Livestock Research Institute (ILRI).