The potential of two rough-seeded lupin species (Lupinus pilosus and L-atlanticus) as supplementary feed for sheep

The rough-seeded lupins are better adapted to alkaline soils than the domes ticated lupins currently in use in commercial agriculture in southern Austr alia. Lupinus pilosus and L. atlanticus are two species of rough-seeded lup ins that are undergoing domestication, and could be very valuable for sheep as a supplementary feed. However, there is little information on the nutri tive value of these lupins. Two experiments were conducted to evaluate the nutritive value of L. pilosus and L. atlanticus, compared with L. angustifo lius, which is widely used as an animal feed in Australia. The results show ed that the rough-seeded lupins examined had larger seeds, a greater propor tion of seed coat in the whole seed, and a higher fibre content in the seed coat than domesticated lupins. Nitrogen (N) content in the kernel of the v arious lupin species was similar. The high fibre content in seed coat did n ot appear to limit the digestion of the seeds by sheep as demonstrated by t he high potential degradability of seed dry matter (DM) for all lupin speci es. There were no significant differences between L. pilosus, L. atlanticus , and L. angustifolius as a supplementary feed provided at low levels in DM digestibility (DMD), apparent energy digestibility (AED), and N-balance, s uggesting that L. pilosus and L. atlanticus could be used in place of L. an gustifolius. Also L. atlanticus could be substituted for L. angustifolius a t high levels of supplementation as there were no differences in DMD, AED, apparent N digestibility, and N-balance when these species were fed to shee p as a supplement to barley straw. Supplementation with lupin seed at 150 g / day significantly improved DM intake by 195 g/ day, DMD by 8.7, and AED b y 11.4 percentage units. However, a high level of lupin supplementation in a diet based on barley straw did not increase DMD and AED of the diet.