The growth performance, carcass quality and digestive efficiency of growing pigs were used to compare sweet lupin seed meal (SLSM) to soya bean meal and meat meal as a source of supplementary protein to wheat in diets for pigs, and to study the influence of low levels of lysine and methionine, high levels of crude fibre and oil, and possible toxic factors in SLSM on the use of SLSM in such diets.

The growth rate and food utilization of pigs between 20 and 80 kg live weight were in the order soya bean meal > SLSM > meat meal, but only the difference between soya bean meal and meat meal was significant. These feeds did not differ significantly in their effects on the proportion of lean in the ham. Adding lysine to the SLSM diet improved growth performance but adding methionine did not. The digestibility of crude fibre in diets containing SLSM was greater than that in diets containing soya bean meal; the digestible energy contents of SLSM and soya bean meal were 4·13±0·05 and 4·16±0·08 Mcal/kg dry matter, respectively. Pigs fed on a diet containing 27·5% SLSM grew faster but utilized food as efficiently when fed ad libitum as on a restricted scale of feeding. The subcutaneous fat of pigs fed on SLSM had a higher iodine number than that of pigs fed on soya bean meal.