1. Institute for Animal Breeding and Genetics; University of Veterinary Medicine Hannover; Bünteweg 17p, 30559 Hannover Germany
2. Clinic for Cattle; University of Veterinary Medicine Hannover; Bischofsholer Damm 15, 30173 Hannover Germany
3. Lehr-und Forschungsgut Ruthe; University of Veterinary Medicine Hannover; Schäferberg 1, 31157 Ruthe/Sarstedt Germany