Effects of increasing amounts of Lupinus albus seeds without or with whole egg powder in the diet of growing pigs on performance

In a growth trial with pigs, the effect of the inclusion of 150 and 300 g of Lupinus albus seeds/kg of feed in the diet was investigated. Parameters studied were: growth, feed utilization, digestibility of nutrients, slaughter and carcass characteristics. Spray dried whole egg powder, a specific inhibitor of lectins in L. albus seeds was also added (50 g/kg of feed), with the aim of verifying whether the unfavourable effects of high levels of lupin seeds could be neutralized. Feeding the diet containing 300 g of lupin seeds/kg lowered the average daily gain from 727 to 674 g and feed intake from 2.32 to 2.05 kg, while feed conversion ratio remained unaltered. The presence of whole egg powder in the lupin seed diets did not abolish the negative effects. Apparent faecal digestibility of most nutrients in the diets was not influenced by addition of lupin seeds or egg powder, except for the crude fat fraction, whereas the digestibility coefficient increased from 0.51 to 0.61. Crude fibre digestibility also increased, but only at the lowest lupin seed level. Carcass weight and dressing percentage were lower in the groups fed the highest lupin seed level. Fatty acid profile of backfat was determined and slightly higher proportions of C18:1 were observed when lupin seeds were fed. Possible reasons accounting for the lower performance of animals receiving lupin seeds are discussed, but the exact reason could not be derived from this experiment.