Effects of prepress-solvent extraction on the nutritional value of canola meal for broiler chickens

Abstract

The objective of the experiment was to determine if standard prepress-solvent extraction of canola (low glucosinolate, low erucic acid rapeseed) affects the nutritional value of the resulting meal for broiler chickens. Three sets of samples were collected from all stages of prepress-solvent extraction at a commercial crushing plant and examined for nutritional value. Except for cystine and serine, processing stages up to and including solvent extraction did not affect coefficient of apparent ileal digestibility (CAID). However, the desolventization/toasting process reduced ( P<0.05) lysine content (6.03–5.50 g/16 gN), crude protein CAID (0.81–0.77), lysine CAID (0.87–0.79) and the CAID of all the other amino acids except glutamine, leucine, methionine and serine. Desolventization/toasting increased the coefficient of variation (percent CV) for the CAID of lysine over the solvent extracted meal (5.6% versus 1.4%) and all the other amino acids except glutamine, histidine, leucine, and serine. As expected, apparent metabolizable energy (AME) content decreased ( P<0.05) with expelling and solvent extraction due to the reduced oil content, but was not affected by other processing stages. In conclusion, commercial desolventization/toasting can reduce the content and CAID of many amino acids in canola meal and increase the level of variability in nutritional value between canola meal samples.