1. Department of Livestock Population Genomics, Institute of Animal Science, University of Hohenheim, Garbenstr 17, 70599 Stuttgart, Germany
2. Department of Animal Sciences, Aksum University, Shire P.O. Box 314, Ethiopia
3. Holeta Bee Research Centre, Holeta P.O. Box 22, Ethiopia
4. Department of Mathematics and Statistics, University of Strathclyde, 26 Richmond Street, Glasgow G1 1XH, UK