1. Institute of Ensiling and Processing of Grass, College of Animal Sciences and Technology, Nanjing Agricultural Univ.; Weigang 1 Nanjing 210095 China
2. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences; Beijing 100101 China
3. Laboratory of Animal Feed Science, Division of Animal Science, Dep. of Animal and Marine Bioresource Sciences, Faculty of Agriculture; Kyushu Univ.; Fukuoka 812-8581 Japan