Two experiments were conducted to determine the effects of soybean meal (SBM) level in diets with or without distillers dried grains with solubles (DDGS) on growth performance of late nursery pigs.
A total of 1,064 and 1,011 pigs (PIC 280×1050; initially 10.5±0.36 and 10.9±0.22 kg) were used in Exp. 1 and 2, respectively, with 21 to 27 pigs per pen. Pens were assigned to treatments in a randomized complete block design with 7 replicates per treatment per experiment. Treatments 1 to 3 were diets with 23% DDGS and 21, 27, or 35% SBM. Treatments 4 and 5 were corn-SBM diets with 27 or 35% SBM. Diets were balanced to 1.30% standardized ileal digestible lysine and 2,606 kcal of net energy/kg. Data were analyzed with the GLIMMIX procedure of SAS with pen as the experimental unit and block as a random effect. There was no evidence for treatment × experiment interactions, thus data from both trials were combined. Feeding diets with 23% DDGS decreased (P = 0.033) ADFI and improved (P = 0.033) G: F compared to corn-SBM diets, which may indicate an underestimation of DDGS net energy. When analyzed as a factorial with or without DDGS, pigs fed diets with 35% SBM had a tendency (P = 0.052) for increased ADG and improved (P = 0.001) G: F compared with diets with pigs fed 27% SBM. As SBM increased from 21 to 35% in diets with DDGS, ADG (linear, P = 0.001) and G:F (quadratic, P = 0.007) improved.
In summary, feeding diets with increasing SBM improved growth performance in late nursery pigs.