Prediction models established for net energy and standardized ileal digestible amino acids in regionally sourced fermented soybean meal for growing pigs.

Objective: The study was conducted to determine the available energy and standardized ileal digestibility (SID) of amino acid (AA) in fermented soybean meal (FSBM), and establish prediction equations for growing pigs.

Methods: In Exp. 1 to determine available energy, twenty-four growing barrows (initial body weight = 35.3 ± 3.2 kg) were randomly assigned to two replicated 6 × 6 Latin square designs, each comprising one corn-based basal diet (used in both squares) and five test diets. In Exp. 2 on AA digestibility, twenty-two growing barrows (initial body weight: 48.8 ± 2.8 kg) underwent distal ileal T-cannulation and were arranged to a 3-period crossover design with one nitrogen-free diet and 10 test diets. The inclusion levels of FSBM in the test diets of Exp. 1 and Exp. 2 were 27.49% and 40%, respectively.

Results: The coefficients of variation among FSBM for ether extract (EE), crude fiber (CF), neutral detergent fiber (NDF), and acid detergent fiber (ADF) all exceeded 10%. The digestible energy, metabolizable energy, and net energy (NE) values of FSBM ranged from 15.50 to 18.44 MJ/kg dry matter (DM), 13.98 to 16.72 MJ/kg DM, and 10.10 to 11.05 MJ/kg DM, respectively. The SID values of AA demonstrated variation (p<0.05) for most AA, with the exception of Arg and Lys among indispensable AA, and Glu, Ser, and Tyr among dispensable AA. The best-fitted prediction equation for NE was a model incorporating EE, NDF, and GE (R² = 0.92, p<0.01), while the best-fitted equations for SIDCrude Protein and SIDLys incorporated DM, NDF, and ADF (R² = 0.71, p = 0.097) and CF, ADF, and Ash (R² = 0.83, p = 0.022), respectively.

Conclusion: The NE values of FSBM ranged from 10.10 to 11.05 MJ/kg DM. The NE value, SIDCrude Protein, and SIDLys of FSBM can be well predicted based on nutritional parameters.