Glossary of Terms

  • Total Phosphorus (Total P)
    • All phosphorus found in the diet
      (does not account for availability to animal or utilization in biological functions)
    • Measured directly by traditional mineral analytical techniques
  • Non-Phytate Phosphorus (NPP)
    • Total P minus Phytate P
    • Not a biological measure
    • Biological availability is source dependent
    • Measured indirectly by traditional Phytate P analytical techniques
  • Available Phosphorus (AvP)
    • Biological measure of true digestibility
    • Total P in the feed minus (fecal P minus endogenous P)
    • Subset of Total P as well as NPP
  • Digestible Phosphorus
    • Biological measure of apparent digestibility
    • Total P in the feed minus fecal phosphorus
    • Subset of Total P, NPP as well as AvP
  • Retained Phosphorus (Utilized P)
    • Biological measure
    • The phosphorus that stays in the body
    • Total P minus (fecal P minus endogenous P plus Urinary P)
    • Subset of AvP