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The dietary energy value of solvent-extracted canola meal (CM) is limited by its relative high fibre content. Air classification may allow the separation of CM into a low-fibre, light-particle fraction and a high-fibre, heavy-particle fraction of interest for feeding monogastric and ruminant species, respectively. Crude fibre (CF), acid detergent fibre (ADF) and neutral detergent fibre (NDF) in light-particle fraction were reduced by 96, 34 and 28% compared with CM (83 CF, 165 ADF, 238 NDF g/kg). Brassica (B) napus, Brassica juncea, or their fractions were evaluated feeding 288 weaned pigs (7.1 kg) randomly placed in 72 pens (4 pigs/pen) for 37d according a 2×3 factorial with 12 replicate per treatment. After weaning, pigs were fed a common commercial phase 1 diet for 5 days. Six pelleted wheat-based diets including 200g of either B.napus or B.juncea parent CM, air-classified light or heavy-particle fractions were formulate to provide 10.5 and 10.0 MJ net energy (NE)/kg and 1.27 and 1.15 g standarised ileal digestible lysine/MJ NE and were fed for 9 (phase 2) and 28 d (phase 3), respectively. Phase 3 diets included 80 g acid insoluble ash/kg as a indigestible marker. Pen feed added, orts, and individual pig body weight were measured weekly to calculate average daily feed intake (ADFI), average daily gain (ADG), and feed efficiency (G:F). Pen faecal samples were collected on d 16 and 17 to calculate diet apparent total tract digestibility coefficients (CATTD) of dry matter (DM), gross energy (GE), crude protein (CP) and digestible energy (DE) value.
Pigs fed B. juncea had 3 and 2% higher (P<0.001) CATTD of DM (0.82 vs. 0.79) and GE (0.84 vs. 0.82) than pigs fed B. napus. Feeding the light-particle fraction increased (P<0.001) CATTD of DM (0.82 vs. 0.79), GE (0.84 vs. 0.82), and CP (0.79 vs. 0.77) by 4, 3 and 3% compared with CM, respectively. For the entire trial, pigs fed B. juncea consumed 33 g/d less (P<0.001) feed (723 vs. 756 g/d), had 0.02 higher (P<0.05) G:F (0.735 vs. 0.718 g:g), but ADG (503 vs. 514 g/d) was not different (P>0.05) compared to pigs fed B. napus. Feeding pigs the light-particle fractions did not affect (P>0.05) ADFI (741 vs. 736 g/d), increased (P<0.05) G:F 0.02 (0.739 vs. 0.721 g:g) and tended to increase (P=0.07) ADG (519 vs. 501 g/d) by 18 g/d compared to CM.
In conclusion, air classification of canola meal increased diet nutrient digestibility, but only modestly increased G:F of weaned pigs due to dietary fibre reduction.
Zhou, X., Oryschak, M.A., Zijlstra, R.T. and Beltranena E. (2013). Effects of feeding high- and low-fibre fractions of air-classified, solvent-extracted canola meal on diet nutrient digestibility and growth performance of weaned pigs. Animal Feed Science and Technology, 179; 112– 120. http://dx.doi.org/10.1016/j.anifeedsci.2012.12.002
