LUPINS (L-LUTEUS, L-ALBUS, L-ANGUSTIFOLIUS) AS A PROTEIN-SOURCE FOR YOUNG-PIGS

The nitrogen balance and growth performance of piglets (12-14 kg initi al body weight) were measured to evaluate the nutritive value of meal from Lupinus luteus cultivars 'Amulet' and 'Cybis', Lupinus albus cult ivar 'Hetman', Lupinus angustifolius cultivar 'Saturn' and a commercia l batch of lupin seeds from Australia (ALS). The inclusion level of lu pin seed meal in the barley-based diets ranged from 310 to 410 g kg(-1 ) to provide 120 g of crude protein from each lupin species per kilogr am of diet. The average apparent total tract digestibility of dry matt er (0.91) and crude protein (0.90) in L. luteus diets was as high as i n the control (soybean) diet. The lowest (P < 0.05) digestibility of d ry matter (0.86) and crude protein (0.83) was found for the diet conta ining seed meal from L. albus. Utilization of the apparently digested nitrogen (nitrogen retained as a proportion of nitrogen digested) was highest in the soybean group and both groups with L. angustifolius ('S aturn' and ALS) with values of 0.71, 0.72 and 0.71, respectively. Inte rmediate values were found for L. luteus ('Amulet', 0.68; 'Cybis', 0.6 8) and the lowest (0.55) for the L. albus group. The growth performanc e of pigs given diets with seeds of L. luteus and L. angustifolius was not different from that of pigs given the soybean diet, but pigs give n the L. albus diet had a higher (P < 0.05) feed conversion ratio. It was concluded that L. albus cultivar 'Hetman' was less suitable than o ther varieties as a source of supplementary protein for young growing pigs when included in the diet at the level of 37 g kg(-1). Seeds of L . luteus cultivar 'Cybis' and both cultivars of L. angustifolius were used at levels of up to 41 g kg(-1) in diets without depression of gro wth performance as compared with soybean diet.