1. Department of Animal Science & Technology, Chung-Ang University, Anseong, Gyeonggi-do 456-756, Korea
2. Animal Biotechnology Division, National Institute of Animal Science, RDA, Chuksan-gil 77, Suwon, Gyeonggi-do 441-706, Korea
3. Department of Science, Spokane Community College, 1810 N Greene St., Spokane, WA 99217-5399