3 birds with the closest BW to the average cage BW were killed by cervical
dislocation.
The pH of the gizzard and proventriculus were recorded by immersing the electrode of a digital pH meter into the center of the lumen. The right tibiotarsus
was removed, boiled, and cleaned from adherent tissue for bone-ash determination. The rest of the chicks were fasted for 2 h and killed by cervical dislocation to
determine Ca and P content of the whole body. The 4 whole bodies were minced together and stored for ash, Ca, and P content determination