In vivo digestibility of blue lupin (L. angustifolius), an alternative protein source to soy

Blue lupin can be grown under the conditions prevailing in Switzerland, and its seeds are rich in protein. It could therefore be used as a local alternative to soy imports to meet the protein requirements of ruminants. The aim of this experiment was to determine the in vivo digestibility of organic matter (OMd), crude protein (CPd) and crude fibre (CFd) of lupin seeds, in order to estimate their nutritional value. Sixteen wethers were assigned to four dietary treatments consisting of hay and a 0, 10, 20 and 30 % share of crushed lupin seed, respectively. Lupin OMd, CPd, and CFd were 90.8 %, 89.5 % and 87.7 %, respectively. Whereas, OMd and CFd were similar to actual values from Feedbase, CPd was 4.5 percentage points higher. This leads to an increased net energy for production of 0.2 MJ per kg dry matter.