Nutrient analysis, metabolizable energy, and digestible amino acids of soybean meals of different origins for broilers

摘要

Nutrient composition, ileal amino acid (AA) digestibility, and AME of 55 soybean meal (SBM) samples from the United States (US; n = 16), Argentina (ARG; n = 16), Brazil (BRA; n = 10), and India (IND; n = 13), collected from commercial mills in Southeast Asia, were compared using laboratory analyses and animal studies. There were significant (P < 0.05 to 0.001) differences due to origin in CP, fat, ash, fiber, and nonstarch polysaccharide (NSP) contents of SBM. The average CP content of US, ARG, BRA, and IND samples was determined to be 47.3, 46.9, 48.2, and 46.4% (as-fed basis), respectively. Compared with SBM from other origins, crude fiber and NSP contents were lower (P < 0.05) and sucrose content was higher (P < 0.05) in the US samples. The IND samples had the highest (P < 0.05) contents of fiber, ash, and NSP, and lowest (P < 0.05) contents of fat and sucrose. Differences (P < 0.0001) were observed among origins for in vitro protein quality measures (urease index, KOH protein solubility, and trypsin inhibitor activity). Significant (P < 0.001) effects due to origin were observed for all minerals. Soybean meal from the US and IND had higher (P < 0.05) calcium contents (0.45%) compared with those from ARG and BRA (0.28-0.31%). Phosphorus and potassium contents were lowest (P < 0.05) in SBM from IND, and no differences (P > 0.05) were observed in SBM from other origins. Iron content was markedly high (928 mg/kg) in SBM from IND compared with those from other origins (103-134 mg/kg). Major origin-related differences (P < 0.0001) were observed in the AME of SBM. The average AME content of US, ARG, BRA, and IND samples was 2,375, 2,227, 2,317, and 2,000 kcal/kg (as-fed basis), respectively. Total AA contents of US, ARG, BRA, and IND samples were similar (P > 0.05) for 9 of the 17 amino acids. Major differences (P < 0.05 to P < 0.001) due to origin were determined for the digestibility of all AA. The IND samples had the lowest (P < 0.05) digestibility and no differences (P > 0.05) between samples from other 3 origins. However, the digestible CP content of US SBM was higher (P < 0.05) than those of ARG and IND, but similar (P > 0.05) to that from BRA. The digestible CP contents of SBM from the US, ARG, BRA, and IND were 40.0, 38.6, 39.8, and 36.7%, respectively. Digestible contents of indispensable AA, in general, followed the same trend as that of digestible CP. In conclusion, the present evaluation showed that major differences in nutritive value do exist between SBM from different origins in terms of nutrient contents, AME, and digestible AA. Overall, SBM originating from the US had better nutritive value compared with those from ARG and IND, on the basis of AME and contents of digestible CP and digestible AA.