Growth Performance of Weaned Pigs Fed Raw or Extruded Canola Meal with Low to High Extrusion Intensity

Hydrothermal processes with high shear force such as extrusion cooking may increase solubility of fiber by turning part of insoluble fiber fraction into soluble and may inactivate heat-labile anti-nutritional factors in feedstuffs. Whether extrusion processing of canola meal (CM) can increase nutrient digestibility of CM and growth performance of weaned pigs fed CM diets is unclear. The objective was to determine the effect of extrusion of solvent-extracted Brassica napus CM on growth performance in weaned pigs. The CM was extruded using a single-screw extruder (X-115; Wenger, Sabetha, KS). Extruder intensity ranged from low to high by changing extruder speed (250, 350, 450 rpm) and related mechanical energy. A total of 200 pigs (Duroc × Large White/Landrace F1; Hypor, Regina, SK, Canada) with an initial BW of 8.3 ± 1.7 kg weaned at 21 ± 2 d of age were divided within gender into heavy or light BW. Pigs within each subgroup were placed in a randomized complete block design into pens with 4 pigs per pen reaching 10 pens per diet. Then 14 d after weaning, pigs were fed 1 of 5 diets containing 20% soybean meal (SBM), raw CM, or CM extruded with low, medium, or high extruder intensity for 3 wk. Wheat based diets were formulated to provide 2.3 Mcal NE/kg and 5.1 g SID Lys/Mcal NE. On DM basis, raw CM and extruded CM with low, medium or high extruder intensity contained 5.31, 4.85, 4.51 and 4.78 µmol/g total glucosinolates. The ADFI, ADG, and G:F ratio of pigs did not differ (P > 0.05) among the 5 diets, and did not differ (P > 0.05) between CM diets and the SBM diet for each week and for the entire 3-wk trial. Pig final BW for SBM, raw CM, extruded CM with low, medium or high extruder intensity was 19.5, 19.4, 19.2, 19.8, and 19.8 kg and did not differ (P > 0.05) among diets. In conclusion, extrusion reduced the total glucosinolate content in CM, medium intensity reduced total glucosinolates 15% compared to raw CM. Considering the decrease in glucosinolates, additional extrusion of solvent-extracted Brassica napus CM was expected to increase nutritive quality and palatability of CM. However, extrusion of solvent-extracted Brassica napus CM across a range of intensity using extruder speed and mechanical energy did not affect growth performance of weaned pigs fed diets with CM to replace 20% SBM.