Growth performance of weaned pigs fed raw, cold-pelleted, steam-pelleted, or extruded field pea

Abstract

Field pea is an alternative starch and protein source for swine; however, feeding raw field pea to weaned pigs may reduce feed efficiency (G:F). Growth performance of weaned pigs fed field pea processed using treatments with heat and friction is unknown. To explore the effects of feed processing, field pea was ground (4.0-mm sieve), then either cold-pelleted (70–75 °C), steam-pelleted (80–85 °C) or extruded (115 °C) and then re-ground (3.2-mm sieve). Diets included 400 g per kg raw, cold-pelleted, steam-pelleted or extruded field pea replacing 300 g soybean meal (SBM) and 100 g wheat grain and were formulated to provide 10.0 MJ net energy (NE)/kg and 12.1 g standardised ileal digestible lysine/kg. In total, 236 pigs (weaned at 20 days of age) were housed in 60 pens in 4 rooms and fed 1 of 5 diets starting 2 weeks post-weaning [initial body weight (BW): 10 kg] for 3 weeks. The CATTD of gross energy and crude protein, digestible energy and predicted NE value were lower (P < 0.001) in field pea diets than in SBM diets and were not affected by processing of field pea. Overall (day 1–21), average daily feed intake of pigs fed raw or processed field pea diets (853–882 g/day) was greater (P = 0.001) than pigs fed SBM diet (813 g/day). Average daily gain did not differ between SBM diet and field pea diets, nor did it differ among field pea treatments. Thus, G:F was lower (P < 0.001) for pigs fed field pea diets (0.60–0.63) than for pigs fed SBM diet (0.68), but did not differ among field pea treatments. Final BW of pigs fed raw, cold-pelleted, steam-pelleted, extruded field pea and SBM diets were 21.0, 21.1, 21.3, 21.4 and 21.7 kg respectively. Final BW was not affected (P > 0.05) by feeding or processing of field pea. To conclude, weaned pigs fed 400 g field pea/kg diet in substitution of SBM could maintain growth performance. Greater ADFI for field pea diets than SBM diet indicated that pigs compensated for the reduced energy value of field pea diets. Raw field pea can be included in late nursery diets without thermal treatment to replace 300 g SBM and 100 g wheat grain/kg diet.