1. Department of Anatomy, Faculty of Veterinary Medicine University of Khartoum Khartoum Sudan
2. Department of Anatomy and Molecular Embryology Ruhr University Bochum Bochum Germany
3. Department of Animal Breeding and Genetics University of Khartoum Khartoum Sudan
4. Department of Animal Breeding, Faculty of Organic Agricultural Sciences University of Kassel Witzenhausen Germany