1. Department of Animal and Range Sciences, New Mexico State University, Las Cruces 88003
2. Department of Animal Breeding and Genetics, University of Agriculture, Abeokuta 11001 NGR
3. Department of Animal Science, Iowa State University, Ames 50011
4. Department of Animal Science, Adnan Menderes University, Aydin 09100 Turkey
5. Department of Animal Sciences, Kansas State University, Manhattan 66506
6. Department of Animal Sciences, Colorado State University, Fort Collins 80523