This study was conducted to determine the standardized ileal digestibility (SID) of amino acids (AA) in hydrolyzed feather meal (HFM), flash dried poultry protein (FDPP), poultry meal (PM), and meat and bone meal (MBM) fed to broiler chickens and pigs. Four semi-purified diets and a nitrogen-free diet were prepared.

Exp. 1 was conducted with 416 male broiler chickens (initial body weight [BW] = 705 ± 100.0 g) at d 18 post-hatching in a randomized complete block design. Birds were fed diets for 5 d and then euthanized to collect ileal digesta.

In Exp. 2, ten barrows (initial BW = 22.1 ± 1.59 kg) surgically fitted with T-cannulas at the distal ileum were assigned to duplicate 5 × 4 incomplete Latin square design with 5 diets and 4 periods.

There were 5-d adaptation and 2-d ileal digesta collection periods in each experimental period. Data were analyzed as a 2 × 4 factorial arrangement with the effects of species (i.e., broiler chickens and pigs) and four experimental diets. There were interactions (P < 0.05) in the SID of His, Lys, Thr, Trp, and Val between diets and species. In broiler chickens, the SID of Lys in MBM was greater (P < 0.05) than HFM and FDPP but was not different from PM.

Pigs fed MBM had greater (P < 0.05) SID of Lys than HFM, FDPP, and PM. In broiler chickens, the SID of His, Thr, and Trp in FDPP and PM were greater (P < 0.05) than HFM but was less (P < 0.05) than MBM. In pigs, the SID of His, Thr, and Trp in FDPP and PM were greater (P < 0.05) than HFM but was not different from MBM.