THE EFFECTS OF MOIST HEAT AND AMMONIA ON THE CHEMICAL COMPOSITION AND FEEDING VALUE OF EXTRUDED CANOLA SCREENINGS FOR MICE

Abstract

Canola screenings were exposed to moist heat and ammonia during extrusion. The extruded canola screenings (ECS) were then analyzed for chemical components and used in feeding trials to assess their value as a protein and energy supplement. Extruded canola screenings were incorporated into diets at 8.2, 23.4 and 38.6% and fed to weanling male mice for a 2-wk growth period. The interaction of moist heat and ammonia reduced (P < 0.05) the content of glucosinolates and neutral detergent fiber. The addition of ECS to mouse diets increased protein digestibility (P < 0.01) and decreased energy digestibility (P < 0.01). An increase in the extrusion temperature decreased both protein and energy digestibility of the ECS. Increasing the level of ECS in the diet improved mouse weight gains and feed efficiency but decreased intake. Mice fed screenings extruded at higher temperatures had lower weight gains and feed efficiencies. Relatively high fiber and ash levels lowered the feeding value of ECS as a protein supplement when compared to SBM but at low levels of inclusion (≤ 23%), mice fed ECS had comparable weight gains and feed intakes. Key words: Canola screenings, extrusion, moist heat, ammonia, mice