The decreased fecal P excretion
and increased P absorption and digestibility that was
observed as OMM was added to the corn–SBM diet indicate
that supplementation with OMM may improve
the efficiency of P absorption. The likely reason for this
observation is that OMM may reduce the formation of
complexes between P and other minerals, such as Zn and
Ca, and, therefore, increase P absorption in the small intestine.
Another possible reason is that the HMTBa released
from the organic minerals may increase phytate P
utilization as reported by Liem et al. (2008), although the
mechanism is not clear. Compared with corn–SBM diets,
the increased ATTD of P in the corn grits diets is mainly
due to the reduced level of phytic acid in these diets