Energy concentration and amino acid digestibility in high-protein canola meal, conventional canola meal, and soybean meal fed to growing pigs

Two experiments were conducted to determine DE and ME and the standardized ileal digestibility (SID) of CP and AA in 2 sources of high-protein canola meal (CM-HP1 and CM-HP2), conventional canola meal (CM-CV), and soybean meal (SBM) fed to growing pigs. In Exp. 1, 40 barrows (51.5 ± 4.0 kg initial BW) were housed in metabolism cages and randomly allotted to 1 of 5 diets with 8 replicate pigs per diet. A corn-based diet (97.4% corn) and 4 diets that contained both corn and each of the 3 sources of canola meal or SBM were formulated. Feces and urine were collected for 5 d after a 5-d adaptation period. The DE and ME were 3,347 and 3,268 kcal/kg in corn, 3,312 and 2,893 kcal/kg in CM-HP1, 3,627 and 3,346 kcal/kg in CM-HP2, 2,798 and 2,492 kcal/kg in CM-CV, and 4,000 and 3,796 kcal/kg in SBM, respectively. Values for DE and ME were greater (P < 0.05) in SBM than in all other ingredients, but DE and ME were greater (P < 0.05) in corn and the 2 high-protein canola meals than in CM-CV. The DE and ME were also greater (P < 0.05) in CM-HP2 than in CM-HP1. In Exp. 2, 10 barrows (65.3 ± 10.4 kg initial BW) were equipped with a T-cannula in the distal ileum and randomly allotted to a replicated 5 × 5 Latin square design with 5 diets and 5 periods in each square. A N-free diet and 4 corn starch-based diets that contained CM-HP1, CM-HP2, CM-CV, or SBM as the sole source of AA were formulated. Each period lasted 7 d and ileal digesta were collected on d 6 and 7 of each period. The SID of CP and all AA except Pro were greater (P < 0.05) in SBM than in the 3 sources of canola meal. With the exception of His and Lys, no differences in SID of indispensable AA were observed among the 3 sources of canola meal. The SID of His and Lys were greater (P < 0.05) in CM-HP1 and CM-HP2 than in CM-CV and the SID of CP was greater (P < 0.05) in CM-HP2 than in CM-CV, but no differences in the SID of indispensable AA were observed between CM-HP1 and CM-HP2. In conclusion, the 2 high-protein canola meals used in this experiment have ME values that are not different from corn but greater than in CM-CV. The SID of most AA is greater in SBM than in canola meals, but SID of His and Lys are greater in high-protein canola meals than in CM-CV. As a consequence, high-protein canola meals supply more ME and SID of AA for growing pigs than CM-CV.