Additionally, the AID and SID of most AA, especially Lys (0.73 vs. 0.54, 0.77 vs. 0.56) and His (0.74 vs. 0.54, 0.77 vs. 0.56), in EFM (Table 4) were greater than those in feather meal published in NRC
(2012), maybe because of differences in the producing processes. The low content of SID Met and Trp in EFM implies that
these may be limiting AA, which indicates that diets based on EFM protein may require more AA supplementation to meet
dietary requirements for AA.