The objective was to determine metabolizable and bioavailable energy content of soybean gums and soap stocks using precision-fed roosters and both restrict-fed and ad libitum-fed broiler chickens. In Experiment 1, nitrogen-corrected true metabolizable energy (TMEn) of gums and soap stocks relative to refined soybean oil was determined using precision-fed adult Single Comb White Leghorn roosters. Diet 1 was 85% corn and 15% Solka Floc. Diets 2 through 7 were the same as diet 1, except 7.5 or 15% soybean oil, gums, or soap stocks were added in place of Solka Floc. In Experiment 2, TMEn of soybean meal (SBM) with 4% inclusion of gums and soap stocks was measured in precision-fed roosters. In Experiments 1 and 2, roosters were fasted for 26 h, precision-fed 25 g of diets, and excreta were quantitatively collected for 48 h. In Experiment 3, relative bioavailable energy (RBV) of gums and soap stocks was determined in restrict-fed broilers. Energy-deficient diets containing 0, 5, or 10% soybean oil, gums, or soap stocks were fed from 10 to 21 d-of-age. In Experiment 4, nitrogen-corrected apparent metabolizable energy (AMEn) was determined in SBM with 4% inclusion of gums and soap stocks using ad libitum-fed broilers from 19 to 22 d-of-age. In Experiment 1, TMEn increased with lipid inclusion (P < 0.05). The TMEn of gums and soap stocks relative to soybean oil was 53 and 45% (as-fed basis) and 79 and 81% (DM basis), respectively. In Experiment 2, the addition of 4% gums and soap stocks increased TMEn of SBM (P < 0.05). In Experiment 3, RBV of gums and soap stocks ranged from 40 to 51% (as-fed basis) and 73 to 77% (DM basis) relative to soybean oil in broilers. In Experiment 4, the addition of 4% gums and soap stocks increased AMEn of SBM (P < 0.05) in broilers. In conclusion, soybean gums and soap stocks are viable lipid energy sources in poultry diets, particularly when moisture content is reduced.

Read the full paper here.

Wells, S., S. Hufford, R. Drysdale, L. Parisi, K. Gaffield, M. Kidd and B. Parsons. 2026. Metabolizable and bioavailable energy of soybean gums and soap stocks determined in precision-fed roosters, restrict-fed broiler chickens, and ad libitum-fed broiler chickens. Poultry Science Volume 105, Issue 6, June 2026, 106761, https://doi.org/10.1016/j.psj.2026.106761

Read the abstract from the 2025 PSA meeting that covers Experiments 1 and 2 of this work here.