Quality Control Parameters for Commercial Full-Fat Soybeans Processed by Two Different Methods and Fed to Broilers

Abstract

Full-fat soybean (FFSB) samples obtained from 2 experiments already published were analyzed in vitro for urease activity (UA), Soy-Chek score, trypsin inhibitor (TI) activity, and KOH protein solubility (KOHPS). Samples were also analyzed in vivo for amino acid digestibility using the precision-fed cecectomized rooster assay at the University of Illinois. Samples from experiment 1 corresponded to 6 temperature treatments in a commercial extruder: raw, 118, 120, 122, 126, and 140°C. Samples from experiment 2 corresponded to 6 temperature treatments along with different retention times in a commercial toaster: raw, 113, 120, 130, 135, and 150°C, and 0, 3.0, 4.5, 6.5, 7.0, and 9.5 m, respectively. In vitro results were compared with the already published performance data. The TI and UA were significantly (P < 0.05) correlated to BW and feed conversion ratio in both experiments. There was no correlation in any experiment between KOHPS and performance data, except for feed conversion ratio in experiment 1. Less than 18,000 TI units/g or less than 0.10 pH units of UA are adequate for optimum broiler chicken performance. Both performance and in vivo amino acid digestibility data failed to demonstrate that FFSB were overprocessed in any of the experiments, even though solubility values dropped as temperature treatment increased.