Growth Performance, Organ Weights, and Blood Parameters of Nursery Pigs Fed Diets Containing Cold-Pressed Canola Cake

An experiment was conducted to determine effects of including cold-pressed canola cake (CPCC) in diets for nursery pigs on growth performance, visceral organ weights relative to live BW, and blood parameters. A total of 160 pigs (7.8 kg BW), which had been weaned at 21 d of age and fed a commercial starter diet for 7 d, were housed in 40 pens (4 pigs/pen) and fed 4 diets (10 pens/diet) in a randomized complete block design for 35 d. The 4 diets were corn-soybean meal (SBM)-based basal diet and the basal diet with corn and SBM replaced by 20, 30, or 40% of CPCC. The diets were fed in 2 phases; Phase 1 from d 1 to 14 and Phase 2 from d 15 to 35. Diets in each phase were formulated to meet NRC (2012) nutrient recommendations for nursery pigs and to have same NE; standardized ileal digestible (SID); Lys, Met, Thr, and Trp; and available P contents. Phase 1 diets contained 2,485 kcal/kg NE; 1.35% SID Lys, 0.39% SID Met, 0.79% SID Thr, 0.24% SID Trp, and 0.40% digestible P. Phase 2 diets contained 2,473 kcal/kg NE; 1.23% SID Lys, 0.36% SID Met, 0.73% SID Thr, 0.22% SID Trp, and 0.33% digestible P. Feed intake and BW were determined by phase, whereas organ weights and blood parameters were determined on d 35. On DM basis, CPCC contained 39.6% CP, 2.32% SID Lys, 0.74% SID Met, 1.63% SID Thr, 0.50% SID Trp, 16.0% EE, 18.4% NDF, and 14.9 µmol/g of glucosinolates. Increasing dietary CPCC from 0 to 40% linearly reduced (P < 0.05) overall (d 0 to 35) ADG and ADFI (0.440 to 0.288 kg/d and 0.739 to 0.522 kg/d, respectively). Increasing dietary CPCC from 0 to 40% linearly increased (P < 0.05) liver and thyroid gland weights relative to BW by 16 and 44%, respectively; but linearly reduced (P < 0.05) serum tetraiodothyronine concentration by 19%. No differences were observed in heart and kidney weights relative to live BW; and in serum triiodothyronine concentration due to dietary CPCC. In conclusion, increasing dietary level of CPCC from 0 to 40% by decreasing dietary corn and SBM levels depressed growth performance, increased metabolic activity in liver and thyroid gland, and reduced tetraiodothyronine level in serum of pigs. Thus, the amounts of CPCC included in nursery pig diets should be based on the targeted growth performance and price of CPCC.