Phosphorus Nutrition

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Phosphorus Nutrition
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• 1998 Maryland Water Quality
  Improvement Act
• Livestock farms must have a certified animal
  waste nutrient management plan based on P and N
  in place by July 1, 2005.

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Phosphorus Roles in the Body

• Quantitatively, 80 of all phosphorus is located
  in the bones and teeth precipitated with calcium.
  .

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Phosphorus Involvement in Metabolism

• Phospholipids cellular membranes
• Oxidative phosphorylation electron transport
  and oxidative metabolism
• Pyridoxal phosphate amino acid catabolism
• 4-phosphopantetheine core of Acyl Carrier
  Protein which is a key to de novo fatty acid
  biosynthesis
• Phosphoproteins casein in milk

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Phosphorus Involvement in Metabolism (contd)

• Lipophosphoproteins plasma lipid transport
  proteins (VLDL, LDL, HDL)
• Enzyme Regulation
• Glycogen Phosphorylase
• Phosphorylase A ---- Phosphorylase B
• (active) (less
  active)

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Factors Influencing Phosphorus Digestion and
Absorption

• Phosphorus intake
• Calcium intake (CaP ratio)
• Vitamin D status
• Intestinal pH
• Age of animal
• Intake of other minerals and dietary fat

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Phytate Phosphorus

• Phytic acid Myo-inositol 1,2,3,4,5,6 hexakis
  dihydrogen phosphate
• Phytate salt of phytic acid
• Phytase An enzyme that catalyzes the release of
  phosphate groups from phytate
• 3-phytase microbial origin
• 6-phytase plant origin

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Myo-Inositol Hexakisphosphate (IP6)
P C H O
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Myo-Inositol Hexakisphosphate (IP6)
6
1
2
5
3
4
P C H O
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Myo-Inositol Hexakisphosphate (IP6)
Fe
Zn
Ca
Starch
Protein
Ca
P C H O
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Phytate Effects on Mineral Nutrition

• Six phosphoric acid residues have various
  affinities for other cationic minerals
• One mole of phytic acid can bind an average of 3
  to 6 moles of Ca
• At neutral pH, strong affinities for Zn and Cu
  make them largely unavailable
• Negative effect on protein solubility and pepsin
  activity under acidic pH conditions

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Phytate Literature

• Common, R.H., 1939. Phytic acid in
• mineral metabolism in poultry.
• Nature 143379-380.
• Lowe et al., 1939. Cereals and rickets.
• The availability of phytin-P to the chick.
• Poultry Sci. 1840-44.

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Phytate Literaturecontd

• Mollgaard, H., 1946. On phytic acid, its
  importance in metabolism and its enzymic cleavage
  in bread supplemented with calcium. Biochem. J.
  40589-603.
• Mellanby, E., 1949. Rickets-producing and
  anticalcifying action of phytate.
• J. Physiology 109488-533.

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Phosphorus Digestibility
PHOSPHORUS
PHOSPHORUS

INTAKE
EXCRETA
( FECES )
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Phosphorus Excretion in Swine (Pallauf and
Rimbach, 1996)
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Digestibility of Phosphorusin Plant Feedstuffs
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Supplemental Phosphorus Sources
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Digestibility of Phosphorus in Feedstuffs of
Animal Origin
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Phosphorus Variability in Ingredients(Wicker,
1999)
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Phosphorus Variability in Ingredients(Wicker,
1999)
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Phosphorus Availability

• Digestibility is a function of what is consumed
  and excreted (recycled)
• Availability is a comparison of sources

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Apparent Digestibility of Inorganic Phosphorus in
Poultry and Swine(Adapted from Jongbloed 1992,
1997)
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Phytase Enzyme

• Plant phytase
• pH optimum 4.0-6.0
• Microbial phytase (Aspergillis ficium)
• pH optimums of 2.5 and 5.5, although the enzyme
  is 40 less active at pH 2.5

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Phytase Literature

• Anderson, R.J., 1915 a. The hydrolysis of
  phytin by the enzyme phytase contained in wheat
  bran. J. Biol. Chem. 20475-482.
• Anderson, R.J., 1915 b. The hydrolysis of the
  organic phosphorus compound of wheat bran by the
  enzyme phytase.
• J. Biol. Chem. 20482-491.

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Phytate Phosphorus and Phytase Activity of Common
Feedstuffs
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Ileal absorption of feed components in laying
hens fed diets containing phytase.(Klis and
Versteegh, 1991)
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Aspergillus niger conidiophores and conidial
heads (phase- contrast microscopy)
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Dietary P and Phytase Excretion in Broilers
(Jongbloed, 1992, 1997)
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Experimental Poultry Diets(Reed and Lilburn,
2001)
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Phosphorus and Nitrogen Experiment(Reed and
Lilburn, 2001)
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Phosphorus in the Future

• Low phytate corn (lpa 1-1 allele)
• Same total P (.26), .21 vs .08 Phytate-P
• (Li et al., 2000)
• Soybeans transformed with a fungal phytase gene
• ( Denbow et al., 1998)
• Organic versus Inorganic P migration in soil

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Calcium absorption
CBP
Ca2
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