1. Acocks, J.P.H., 1988. Veld Types of South Africa. Memoirs of the Botanical Society of South Africa. No. 57, 3rd ed. Botanical Research Institute, Department of Agriculture and Water Supply, South Africa.
2. Predicting amino acid adequacy of diets fed to Holstein steers;Ainslie;J. Anim. Sci.,1993
3. Anonymous, 1984. Climate of South Africa—Climate Statistics Until 1984. Department of Environmental Affairs, Pretoria.
4. Anonymous, 1993. Annual Weather Report for 1993. Department of Environmental Affairs and Tourism, Pretoria.
5. A.O.A.C., 1997. Official Methods of Analysis, 15th ed. Association of Official Analytical Chemists, Arlington, VA, USA.