DIGESTIBILITY AND ENERGY VALUE OF SWEET LUPIN SEED (LUPINUS-ALBUS VAR MULTOLUPA) IN PIGS

The seed of L. albus var. multolupa contained 413.0 g crude protein, 81.3 g ether extract, 130.0 g crude fiber, 334.0 g N-free extract, 42.3 g ash, 1580 mg Mn/kg dry matter and trace amounts of total alkaloids (< 0.01%). Lys and Met were limiting (16.9 and 2.7 g/kg dry matter, respectively). Digestible energy (DE) metabolizable energy (ME) values of a diet based on barley supplemented with lupin seed meal (31%) were 15.4 and 14.7 MJ/kg dry matter, respectively. The digestibility of the dietary protein was 84.4%. An unexpected crude fiber digestibility of 60.2% was also found. Energy values of the seed of L. albus var. multolupa were high (DE, 18.1; ME, 16.9 MJ/kg dry matter). The low level of lignin of this seed accounted for the digestibility values of crude fiber neutral detergent fiber (NDF) and acid detergent fiber (82.5, 83.2 and 87.8%, respectively). The high digestibility of lupin protein (88.6%) probably indicated the absence of anti-nutritional factors. In comparison with other lupin species, the seed of L. albus var. multolupa could be included at higher levels in practical cereal-based pig diets as a substitute for other protein concentrates, providing that adequate amounts of Lys and probably Met were supplied.