Meal residual oil level and heat treatment after oil extraction affects the nutritive value of expeller pressed canola meal for broiler chickens

This experiment determined the effects of expeller-pressed canola meal (EPCM) residual oil (10% vs. 14%) and heat treatment at 115 °C for 25 min on the nitrogen-corrected apparent metabolizable energy (AMEn) value and amino acid (AA) digestibility for broilers. Day-old male chicks (six per cage) were fed six test diets (five cages per diet) from 14 to 21 d using the substitution method in a 2 × 2 factorial design. Increasing EPCM oil content from 10% to 14% increased (P < 0.05) EPCM AMEn value by 287 kcal kg-1. There was heat treatment by oil level interaction (P < 0.05) on standardized ileal digestibility of arginine, isoleucine, leucine, lysine, phenylalanine, threonine, and valine for EPCM in which heat treatment of the low oil EPCM reduced (P ≤ 0.0012) the digestibility of all these AA, but heat treatment of the high oil EPCM only reduced lysine digestibility. In conclusion, heat treatment of EPCM reduced its AMEn value and digestibility of some AA. The AA digestibility of EPCM with low oil was reduced more by heat treatment than EPCM with high oil content, implying that the negative effects of heat treatment on AA digestibility increases with a decrease in residual oil content in EPCM.