High oleic oil soybeans can produce high-quality protein meals, and their fatty acid content can improve several metabolic processes in broilers. However, its amino acid (AA) digestibility has not been determined. The objective of this study was to determine the apparent (AID), and standardized ileal AA digestibility (SID) of high oleic full-fat (HO-FF) soybean meal (SBM) compared to normal oleic full-fat (NO-FF), extruded expeller (NO-EE), and solvent extracted (SE) SBM in broilers. The extruded SBM were all processed under similar conditions, and particle size was uniformized by roller-milling to obtain a geometric mean of 915-950 mm. The HO-FF contained 38.18% crude protein (CP), 18.21% fat, the NO-FF, 38.31% CP and 18.21% fat, the NO-EE 43.80% CP and 8.99% fat, and the SE SBM 47.15% CP and 2.57% fat. A nitrogen-free basal diet (NFD) was fed to one treatment with ten chicks/cage to determine basal endogenous losses (BEL). This NFD contained 78% corn starch, 6.5% dextrose, 5% soybean oil, 3% Solka flock, and 1% Arbocel as fiber sources, plus vitamins and minerals. Titanium dioxide was used as an inert marker to calculate AA digestibility. The test diets contained 57.5% of the basal NFD and 42.5% of each of the four SBM sources. In this experiment, 272 Ross 708 male broilers were placed in 40 battery cages and assigned to five treatments, with eight replicates per treatment, using a completely randomized design. A common starter diet was provided to all the chickens for 14 d. All chickens had similar (P>0.05) BW, feed intake, and FCR before offering the NFD and the four test diets. Experimental diets were provided in the mash during nine days of adaptation. Chickens were euthanized with CO2 at 24 d, and the ileal distal portion contents were collected, frozen, and freeze-dried. The BEL were similar to values found within the literature. The AA AID of the HO-FF SBM was similar (P<0.001) to the NO-FF SBM but lower than the observed in NO-EE and SE SBM for Lys, Met, Val, Leu, Ile, Arg, Asp, Ala, Glu, Gly, and Ser. However, the AID of Thr, Trp, and Cys of HO-FF was similar to the NO-EE but always lower than SE SBM. The SID in the HO-FF SBM was 88.10, 87.60, 81.73, 82.02, 83.18, 82.05, 85.07, and 91.29% for Lys, Met, Thr, Val, Leu, Ile, Trp, and Arg, respectively. These SID for HO-FF were lower than SE and NO-EE SBM but slightly higher than NO-FF SBM. The AA and CP digestibility reduced (P<0.001) from SE, NO-EE, HO-FF to NO-FF SBM. Values of SID of all AA for SE and NO-EE SBM were similar to those reported in the literature for high-protein and high-quality SBM.
In conclusion, the SID of AA from HO-FF is similar to other full-fat SBM and lower than normal oleic extruded expeller and solvent extracted SBM.