Nutritional value of full-fat green canola seed fed to growing-finishing pigs

Immature green canola seed (full-fat green canola seed [FFGC]) is rejected by canola crushing plants due to chlorophyll staining of oil destined for human consumption. With >35% oil, FFGC can contribute energy to pig diets. The nutritive value of FFGC for growing-finishing pigs was determined in 2 studies. In Exp. 1, 6 ileal-cannulated barrows (46.5 kg BW) were fed 3 diets as a replicated 3 × 3 Latin square to determine standardized ileal digestible (SID) coefficients of AA and calculate DE and NE values for FFGC. A diet including 40% FFGC replaced wheat in a basal diet and a cornstarch-based N-free diet were fed to determine energy and nutrient digestibility by difference and to estimate basal endogenous AA losses to calculate SID of AA. In Exp. 2, 1,100 pigs (32.9 kg BW), housed in 50 pens of 22 barrows or gilts per pen, were fed 5 diets including 0, 5, 10, and 15% constant or declining amounts (15, 10, 5, 0, and 0%, respectively) of FFGC over 5 phases to determine effects of feeding FFGC on growth performance and carcass characteristics. Phase diets were formulated to provide 4.00, 3.60, 3.25, 2.90, and 2.65 g SID Lys/Mcal NE for d 0 to 21, d 22 to 42, d 43 to 62, d 63 to 74, and d 75 to 123 kg market weight. Carcass characteristics were measured using the Destron grading system. On DM basis, FFGC contained 43% ether extract, 25% CP, 22% NDF, 10 μmol/g glucosinolates, 1.35% Lys, 0.5% Met, 0.9% Thr, and 0.27% Trp. In FFGC, SID coefficients of Lys, Met, Thr, and Trp were 86.9, 87.3, 76.9, and 84.3%, respectively, and calculated DE and NE values were 4.92 and 3.50 Mcal/kg of DM, respectively. Overall, increasing dietary FFGC inclusion from 0 to 15% linearly decreased (P < 0.05) G:F, carcass weight, and dressing percentage (0.392 to 0.381 kg/kg, 96.7 to 95.7 kg, and 78.4 to 77.8%, respectively) and tended to decrease (P = 0.078) ADG. Pigs fed decreasing amounts of FFGC by growth phase compared with controls (0% FFGC) had lower (P = 0.011) overall G:F (0.392 vs. 0.372 kg/kg). Increasing dietary FFGC inclusion did not affect carcass backfat thickness and loin depth. The FFGC was a good source of dietary energy and AA. However, increasing dietary FFGC inclusion for pigs reduced G:F and dressing percentage likely because of the increased dietary fiber content, resulting from increasing FFGC and barley and reducing wheat, soybean meal, and tallow in diets. Inclusion of FFGC in swine diets should, therefore, be based on targeted G:F and relative cost to other feedstuffs.