EVALUATION OF FABA BEANS (VICIA-FABA CV FJORD) AND SWEET LUPINS (LUPINUS-ALBUS CV KIEV) AS PROTEIN-SOURCES FOR GROWING PIGS

Three diets were formulated to contain 16% crude protein (CP), 12.8 MJ/kg digestible energy (DE) and 0.9% lysine on an air-dry basis. The diets either contained 8.3% fishmeal, 20% faba beans plus 7.9% soybean oilcake meal (SBOK) or 20% low alkaloid lupins plus 8.8% SBOK as protein sources. The latter two diets were compared in a metabolism and nitrogen (N) balance trial using a completely randomized design and six pigs/treatment. All three diets were evaluated in a growth trial using 10 pigs (five boars and five gilts) over the growth interval 30-90 kg. The experimental design was a 3 (diets) x 2 (sex) factorial. Carcass characteristics were determined at the end of the growth trial. Pigs in the metabolism and N balance trial consumed 5% less (P less than or equal to 0.01) of the lupin diet compared to the faba bean diet (1 370 vs. 1 440 g/d). No significant differences in the digestible energy (DE) content and in apparent N retention between the two diets occurred. In the growth trial lower intake levels (P less than or equal to 0.01) were once again observed in pigs on the lupin diet (2 489 g/d) compared to the faba bean (2 637 g/d) and fishmeal diets (2 668 g/d). Pigs on the lupin diet grew (P less than or equal to 0.01) slower than pigs on the other two diets (768 g/d vs. 857 g/d and 869 g/d for the faba bean and fishmeal diets respectively). The feed conversion ratio of pigs on the lupin diet (3.27 kg/kg gain) tended to be poorer than for those on the faba bean (3.03 kg/kg gain) and fishmeal diets (3.12 kg/kg gain). No significant differences were observed in dressing percentage (mean value of 78%), eye muscle area (mean value of 41.3 cm(2)) or P-2-back-fat thickness (mean value of 16 mm) of pigs on the different diets. Both faba bean and low alkaloid lupins can be used at levels of up to 20% in diets of growing pigs, although lower production figures may be expected on lupin diets.