The last 20 years of research in South Africa on feeding standards is reviewed. A major contribution to quantitating energy requirements for growth has been the advent of growth-curve analysis which enable accurate pattern description of genotype and dietary responses. It has been established that indigenous cattle and sheep very often differ from their exotic counterparts in composition of gain and efficiency of feed utilization because of animal- feed interaction. Therefore, they would most probably also differ in most of the feed requirements for growth. A large proportion of the effort in protein metabolism research concentrated on NPN utilization, but progress, as abroad, has been hampered by unsatisfactory techniques to quantitatively distinguish between microbial protein and undegraded feed protein reaching the duodenum. Mineral metabolism research established toxic levels of and antagonisms between a number of minerals.