Effects of Processing Method on Performance and Nutrient Digestibility in Growing-finishing Pigs Fed Lupine Seeds

Three trials were conducted to study the effect of processing method on performance, apparent nutrient and amino acid digestibilities in growing-finishing pigs fed lupine seeds. Ground, expanded or flaked lupine seed was prepared for the trials. In trial 1, a total of 72 growing barrows ($Landrace{\times}Large$ $White{\times}Large$, initial BW of $54.22{\pm}5.87$ kg) were allocated to three treatment diets containing 15% percent of differently processed lupine seed for 28 days. Each treatment had four replicates comprising 6 pigs each. In trial 2, a total of 48 finishing barrows ($Landrace{\times}Large$ $White{\times}Large$, initial BW of $84.40{\pm}6.84$ kg) were subjected to three treatments for 21 days. The experimental design was the same as trial 1 except for supplementation with 20% of lupine seed. Each treatment had four replicates comprising 4 pigs each. To evaluate the ileal digestibility of amino acids, a total of 9 barrows ($Landrace{\times}Large$ $White{\times}Large$), with an average initial BW of $41.07{\pm}1.98$ kg, were fed with ground, expanded or flaked lupine for 7 days. Each pig was surgically equipped with a simple T-cannula fitted in the distal ileum. Amino acid composition and presence of anti-nutritional factors (ANFs) in processed lupine sources were also evaluated. The results showed that there was no significant difference (p>0.05) in lupine amino acid composition due to the different processing methods. Expanded and flaked lupine significantly decreased (p<0.05) the concentration of ANFs compared with ground lupine. There was no effect (p>0.05) on the growth performance in growing pigs. However, processing method had a significant effect (p<0.05) on average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR) in finishing pigs. There was no effect (p>0.05) of the different processing methods on the digestibility of dry matter (DM), gross energy (GE), ether extract (EE), Calcium (Ca) and phosphorus (P), but expanded lupine could significantly increase (p<0.05) the apparent digestibility of CP in finishing pigs. Furthermore, expanded lupine had a higher (p<0.05) apparent ileal digestibility for most indispensable and dispensable amino acids compared with ground and flaked lupine. It was concluded that expanded lupine could be beneficial in improving lupine's quality and improve performance and nutrient utilization in growing-finishing pigs.