Feeding increasing inclusions of canola meal with distillers dried grains and solubles to growing-finishing barrows and gilts

The effect of feeding increasing inclusions of solvent-extracted canola meal (CM) in diets including a relatively high content (150 g/kg) of co-fermented wheat and corn (70:30) distillers dried grains with solubles (DDGS) on diet nutrient digestibility, growth performance, dressing and carcass traits of pigs was evaluated in a commercial-scale study. In total, 550 barrows and 550 gilts [29.9 ± 0.2 kg body weight] housed in 50 pens (22 barrows or gilts) were fed one of 5 dietary regimens over 5 growth phases (3 grower and 2 finisher). Canola meal (0, 60, 120, 180 or 240 g/kg) replaced barley, soybean meal and field pea in diets formulated to equal net energy (NE; 9.7, 9.7, 9.6, 9.4 and 9.4 MJ/kg) and standardized ileal digestible (SID) lysine content (10.9, 9.9, 7.6, 6.7 and 6.2 g/kg). Considering all 5 growth phases, dietary crude protein (CP), crude fibre, acid detergent fibre and neutral detergent fibre increased 13.7, 3.4, 8.2 and 5.8 g/kg, respectively, per each 60 g/kg increase in CM inclusion. Increasing dietary CM inclusion by 60 g/kg decreased (P > 0.05) the apparent total tract digestibility coefficient of gross energy, CP, dry matter, organic matter and ash by 0.01, 0.004, 0.02, 0.01 and 0.04, respectively. For the entire trial (d 0 to 90), increasing dietary CM inclusion by 60 g/kg linearly reduced (P < 0.05) feed intake (ADFI) by 19 g/d and weight gain (ADG) by 7.4 g/d. Increasing dietary CM inclusion resulted in a quadratic response on G:F (ADG/ADFI; P < 0.05). Pigs fed 240 g/kg attained slaughter weight (120 kg) 3 days after pigs fed 60 g/kg CM (linear; P < 0.05). Increasing dietary CM inclusion in diets including 150 g/kg DDGS did not affect carcass weight, dressing, backfat thickness, loin depth, estimated lean yield, or index. In conclusion, increasing dietary CM inclusion from 0 to 240 g/kg in grower-finisher diets including 150 g/kg DDGS had only a minor effect on overall growth performance and did not affect carcass traits of barrows and gilts.