Amino acid digestibility in canola, cottonseed, and sunflower products fed to finishing pigs.

Our objective was to determine the standardized ileal digestibility (SID) of CP and AA in soybean meal (SBM) and canola, cotton, and sunflower products fed to finishing pigs. Each of 8 barrows (average initial BW = 106.6 ± 5.5 kg) were surgically fitted with a T-cannula in the distal ileum. Pigs were allotted to an 8 × 8 Latin square design with 8 diets and 8 periods. The 7 protein ingredients were canola seeds (CS), canola meal (CM), cottonseed meal (CSM), sunflower seeds (SFS), sunflower meal (SFM), dehulled sunflower meal (SFM-DH), and SBM, with each ingredient included as the sole source of AA in the diet. A N-free diet was used to estimate basal endogenous losses of AA. Among tested ingredients, SBM had the greatest (P < 0.05) SID of Lys, and CS had the least (P < 0.05) SID of Phe, Thr, and Tyr. The SID of all indispensable AA except Trp was less (P < 0.05) in CS than SBM, and CM had a greater (P < 0.05) SID of all indispensable AA except Arg, His, Lys, and Trp than CS. However, the SID of all indispensable AA except Arg and Trp were less (P < 0.05) in CM than in SBM. The SID of all indispensable AA except Arg and Trp also were less (P < 0.05) in CSM than in SBM, and the SID of Met was less (P < 0.05) in CSM than in all other ingredients. Among sunflower products, the SID of His, Leu, Phe, and Thr were less (P < 0.05) in SFM-DH than in SFS and SFM, and the SID of Ile, Met, and Val were less (P < 0.05) in SFM-DH than in SFS; however, for CP, Arg, Lys, and Trp, no differences among SFS, SFM, and SFM-DH were observed. The SID of all indispensable AA except Trp were less (P < 0.05) in SFM-DH than SBM, and the SID of His, Ile, Lys, Thr, and Val in SFM were also less (P < 0.05) than in SBM. Except for Lys, no differences between SBM and SFS were observed. In conclusion, the SID of most AA in CS, CM, CSM, SFM, and SFM-DH are less than in SBM.