Concentration of digestible and metabolizable energy and digestibility of amino acids in chicken meal, poultry byproduct meal, hydrolyzed porcine intestines, a spent hen–soybean meal mixture, and conventional soybean meal fed to weanling pigs1

Two experiments were conducted to determine the concentration of DE and ME and the standardized ileal digestibility (SID) of AA in chicken meal, poultry byproduct meal, hydrolyzed porcine intestines, a spent hen–soybean meal (SBM) mixture, and conventional SBM fed to weanling pigs. In Exp. 1, 48 barrows (initial BW: 14.6 ± 2.2 kg) were placed in metabolism cages and allotted to 6 diets with 8 replicate pigs per diet in a randomized complete block design. Six corn-based diets were formulated. The basal diet contained 98.1% corn (as-fed basis) and 5 diets contained corn and 11 to 16% chicken meal, poultry byproduct meal, hydrolyzed porcine intestines, spent hen–SBM mixture, or SBM. All test ingredients were included in their respective diets at levels that were expected to result in similar concentrations of CP among diets. Feces and urine were collected for 5 d. The ME was 3,957, 3,816, 4,586, 4,298, 4,255, and 4,091 kcal/kg DM for corn, chicken meal, poultry byproduct meal, hydrolyzed porcine intestines, the spent hen–SBM mixture, and SBM, respectively. The ME in poultry byproduct meal was greater (P < 0.01) than in corn, chicken meal, the spent hen–SBM mixture, and SBM, and the ME in hydrolyzed porcine intestines and the spent hen–SBM mixture was greater (P < 0.01) than in corn and chicken meal, but there was no difference among hydrolyzed porcine intestines, the spent hen–SBM mixture, and SBM. In Exp. 2, 12 barrows (initial BW: 12.2 ± 1.5 kg) were equipped with a T-cannula in the ileum and allotted to a replicated 6 × 6 Latin square design. A N-free diet and a cornstarch– SBM based diet were formulated. Four additional diets were formulated by mixing cornstarch, sucrose, and SBM with chicken meal, poultry byproduct meal, hydrolyzed porcine intestines, or the spent hen–SBM mixture. The SID of CP and all AA, except Trp and Pro, was greater (P < 0.01) in SBM than in all other ingredients. The SID of CP and all indispensable AA in the spent hen–SBM mixture was also greater (P < 0.01) than in chicken meal and hydrolyzed porcine intestines, and with the exception of Arg and Val, SID values of all indispensable AA in the spent hen–SBM mixture were greater than in poultry byproduct meal. However, with the exception of Val and Lys, there were no differences between chicken meal and poultry byproduct meal. In conclusion, the ME in hydrolyzed porcine intestines and the spent hen–SBM mixture is greater than in chicken meal, but not different from the ME of SBM. Poultry by product meal provides more ME than SBM, chicken meal, and the spent hen– SBM mixture, and the SID of most indispensable AA is greater in the spent hen–SBM mixture than in chicken meal, poultry byproduct meal, and hydrolyzed porcine intestines, but less than in SBM.