is greater in poultry byproduct meal than in
chicken meal and the spent hen–SBM mixture, and the
ME in chicken meal is less than in hydrolyzed porcine
intestines and the spent hen–SBM mixture, but not
different from that in SBM. The AID and SID of AA in
SBM were greater than in all the animal proteins, which
may be a result of relatively high concentrations of
collagen in the animal proteins. Amino acids in the spent
hen–SBM mixture are also well digested by pigs, which
indicates that the spent hen–SBM mixture may be used
as a source of digestible AA in diets fed to weanling pigs.
However, performance experiments need to be conducted
to confirm that the spent hen–SBM mixture may replace
fish meal in diets fed to weanling pigs. The same is true
for the other protein sources used in this experiment