Nutrient digestibility of heat-processed field pea in weaned pigs

Field pea grain can be included in growing-finishing pig diets as an alternative starch and protein source without affecting growth performance. However, for weaned pigs, there is a concern to include field pea grain in diets because of lower energy digestibility compared with soybean meal and corn grain and the presence of trypsin inhibitors that may affect protein digestion. Processing using heat and friction may reduce trypsin inhibitor activity in field pea grain and increase both energy and protein digestibility; however, its effect on weaned pigs remains unknown. To explore, field pea grain was cold-pelleted (70–75 °C), steam-pelleted (80–85 °C) or single-screw extruded (115 °C). The raw and 3 processed field pea grain samples were included in 4 test diets at 956 g/kg and fed to 8 ileal-cannulated weaned barrows (initial body weight, 11.6 ± 1.2 kg) in a double 4 × 4 Latin square. A N-free diet was also fed to pigs to measure basal endogenous losses of amino acids. Cold-pelleting and extrusion reduced trypsin inhibitor activity (TIA) by 0.8–1.1 mg/g in field pea grain. Cold-pelleting increased (P