Evaluation of high-protein canola meals fed to growing chicks and weanling pigs
Three experiments were conducted to determine and compare the nutritional value among 2 high-protein canola meals (CMA and CMB), conventional canola meal (CM-CV), and soybean meal (SBM). The objective of Experiment 1 was to determine P bioavailability in the canola meals and SBM relative to KH2PO4 when fed to growing chicks and to determine if P bioavailability was increased by addition of microbial phytase to a P-deficient CMA diet. Results indicated that as P level was increased by addition of KH2PO4, CMA, CMB, or SBM, weight gain and tibia ash (mg/tibia and %) were increased linearly (P < 0.05). Based on tibia ash %, bioavailabilities of P in CMA, CMB, conventional CM, and SBM relative to KH2PO4 were 15, 20, 13, and 42%, respectively. A linear increase (P < 0.05) in weight gain and tibia ash was observed with addition of KH2PO4 or phytase to the P-deficient CMA diet. The addition of 250 or 500 units/kg microbial phytase to P-deficient CMA diets resulted in approximately 0.13 and 0.18% P being released, respectively, as estimated using the standard curve method. In Experiment 2, the objective was to determine the digestibility of Ca and P in CMA and CMB fed to growing pigs without or with the addition of microbial phytase, and to compare values obtained in high-protein canola meal with digestibility of Ca and P in CM-CV and SBM. Results indicated that apparent total tract digestibility (ATTD) of Ca and P and standardized total tract digestibility (STTD) of P were not different among treatments. Apparent total tract digestibility of Ca was 62, 66, 69, and 73% for CMA, CMB, CM-CV, and SBM, respectively. Standardized total tract digestibility of P was 55, 60, 49, and 66% for CMA, CMB, CM-CV, and SBM, respectively. Inclusion of phytase to the diets reduced both Ca and P outputs (P < 0.05). Inclusion of phytase also improved (P < 0.05) ATTD of Ca and P and STTD of P, regardless of the ingredient in the diet, and there was no interaction between diet and phytase supplementation. In Experiment 3, the objective was to evaluate effects of graded inclusion levels of CMA, CMB, and CM-CV on growth performance, organ weights, bone ash, and blood characteristics of weanling pigs. Results indicated that ADFI was linearly (P < 0.05) decreased if inclusion of CMA, CMB, or CM-CV increased. Average daily gain of pigs fed CMA tended to increase quadratically, with the maximum response observed if 10 or 20% canola meal was included in the diet (P = 0.06). However, G:F was linearly (P < 0.05) increased by adding CMA or CM-CV to the diets. Liver weights were also linearly (P < 0.05) increased if pigs were fed diets containing CMB, but kidney weights were linearly (P < 0.05) decreased by adding CM-CV to the diets. Thyroid gland weights increased linearly (P < 0.05) for pigs fed diets containing CMA. Addition of any of the 3 canola meals linearly (P < 0.05) increased bone ash percentage in the metacarpals. Inclusion of CMA or CM-CV linearly (P < 0.05) decreased serum triiodothyronine, and the inclusion of CMA also linearly (P < 0.05) decreased serum thyroxine in weanling pigs. In conclusion, CMA and CMB contained a numerically higher concentration of bioavailable P when fed to chicks than the CM-CV, and bioavailability was numerically increased with addition of microbial phytase. In contrast, there were no differences observed for ATTD of Ca or P or for STTD of P when the canola meals or SBM were fed to growing pigs. Furthermore, inclusion of any of the 3 canola meals up to 20% in diets for weanling pigs did not reduce growth performance or negatively affect organ, bone, or blood characteristics.
canola meal, chick, digestibility, growth performance, high-protein canola meal, phosphorus, pig
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign