Some aspects of the effect of supplementary energy and/or protein, strategically provided to steers on summer veld, were investigated. 40 Friesland steers in the age group 12 to 18 months were divided into four groups and received the following treatments (quantities of supplements as per animal per day): Group I control, no supplementary feeding; Group 2 strategic supplementation with 1,36 kg maize meat; Group 3 strategic supplementation with 1,36 kg of a mixture consisting of equal parts of maize meal and a high protein concentrate and Group 4 strategic supplementation with 1,36 kg of a high protein concentrate. The greatest response to strategic supplementation in respect of average daily mass gains was obtained with 1,36 kg of high protein concentrate and the poorest response with maize meal. The increased average daily mass gains of Groups 2,3 and 4 was achieved with 8,86; 4,10 and 3,50 kg supplement for each additional kg live mass gain respectively. In spite of significant effects from supplementation on average daily mass gains in two out of three years final live mass was not significantly influenced. Grading of carcasses was also not improved by strategic supplementation. A 90 day fattening period after the summer grazing period improved the grading of carcasses from an initial Grade 3 to Prime.