Two experiments were conducted to evaluate L. albus cv. Buttercup as an alternative to heated full-fat soya bean meal for early weaned piglets. In Experiment 1, the performance of piglets, fed diets with 0%, 4%,8% and 12% lupins and formulated to contain equivalent amounts of digestible energy and lysine, was used to evaluate the effect of increasing levels of commercially produced Buttercup seed in the diet. The results obtained led to Experiment 2, conducted to evaluate certified L. albus cv. Buttercup seed (at an 8% inclusion level) as a partial replacement of full-fat soya beans, The apparent nitrogen and energy digestibilities of the diets were also determined. The commercial Buttercup lupins had an alkaloid content in excess of 0,05% and the certified seed only 0,01%. The digestibility of both energy and protein in the diet was not affected by lupin inclusion. Although statistically non-significant (P>0,05), the retention of digested nitrogen was decreased by about 5 and 7% with lupin inclusion in the two trials, The high-alkaloid seeds in Experiment 1 depressed feed intake by as much as 21%, The low-alkaloid seeds used in Experiment 2 had no effect on feed intake. Growth rate was retarded by 25% when high-alkaloid seeds were used, but by only 6% when low-alkaloid seed was used. Digestible energy utilization was reduced by 2 and 4% with lupin inclusion.