Skip to main content

PHOSPHORUS – How it works & what it actually does!

Published 2nd August 2021 | Article by Graham Shepherd

PHOSPHORUS – How it works & what it actually does!

PHOSPHORUS – How it works & what it actually does!

This follows our previous article on Calcium, which can be read by clicking HERE

In my opinion there is too much talk (and marketing from big firms) about the little micronutrients e.g.zinc, manganese, even chromium!!

It is important to get the big things right first, e.g. Water, Appetite, Energy, Protein, Fibre and the so called MACRO MINERALS, these are Calcium, Phosphorus, Magnesium, Sodium, Potassium, Chloride & Sulphur.

So, today, PHOSPHORUS- you use the word a fair bit, it’s a thing, a fertiliser, a feed ingredient, a problem, a diagnosis. But what does it actually do?

What is Phosphorus?  It’s a highly reactive chemical usually found as salts, such as “phosphates”. This reactivity is useful in energy storage and release- think about striking a match, as this is a phosphorus reaction.

What does Phosphorus do?


Phosphorus is used in some fancy chemistry called the Krebs Cycle in tiny units called Mitochondria, which are the power stations of the body

In the Mitochondria, Phosphorus is used to create energy and power !

Complicated stuff , but the P in the Krebs Cycle Diagram makes the SPARK! –

ATP is basically “3P”, and the extra bond of a P onto ADP/ “2P” stores the energy. When ATP breaks that bond to release the 3rd. P, that releases energy for every process in the body.

Correct Phosphorus levels are needed to :-

  • Provide every function in the body with energy
  • Grow and maintain the structure of bones in the skeleton
  • Keep the cow standing up and walking around
  • Produce a good milk yield
  • Buffer the rumen via saliva

Basic Phosphorus Nutrition-

  • It’s about balance, as is a lot of mineral feeding. The CALCIUM:PHOS ratio or balance is important. Calcium and Phosphorus should be fed in line with each other, and enough of them.
  • Grains and grain by-products (palm kernel, maize gluten feed, distillers) are good sources of phosphorus, but low in Calcium.
  • Phosphorus can be too high, causing Calcium & Vitamin D3 problems, Urine stones, and pollution.
  • There is no benefit to feeding more Phosphorus than is needed.
  • Too much, Too little, Pollution, Costly ingredient = 4 reasons to get it right.

Some Phosphorus related problems in cattle-

  • General lack of production because cows are high performance animals (having a similar relative output to a Tour de France cyclist) and so need 4 x resting energy when at a high yielding stage of lactation.
  • Down Cows- part of milk fever, but cows may creep around, being up at the front, but down on their bag legs (not an uncommon problem in our area of Lancashire). As in milk fever, the problem exists from Calcium and Phosphorus getting sucked into rapid milk and colostrum production.
  • “Red Water” a quite rare low phosphorus condition, but often fatal “Haemoglobin in the urine””, usually around calving. This is caused by low phosphorus causing red blood cell breakage. I have only seen this once, when I was in Canada in a Red Poll!

So, What’s the Plan ?

  1. Involve a Nutritionist to check that you are not over feeding or under feeding Phosphorus to the different classes of stock.
  2. Involve your Vet- Blood samples FROM THE TAIL will indicate if down cows have a “P” component. Do not take samples from the jugular veins because the P is put into the saliva, so jugular samples returning blood from the head is lower in P!
  3. Typically, if low phosphorus is part of the Milk Fever either you get poor response to bottled calcium treatments AND /OR the cows can drag themselves around by their front legs, but not power their back legs (Creeping Cow Syndrome)
  4. Targeted Supplement at Calving. Sometimes cows don’t read the same text books and problems still occur no matter how much nutritional & Veterinary science is used, so in that case, I would suggest using our FOSBOL Bolus on day 1 and 2 of lactation. Benefits of our Fosbol Bolus are:-
    1. A smooth, round ended bolus
    2. A stainless-steel applicator that encloses the full bolus
    3. Fine powdered contents that quickly disperse in the rumen
    4. A readily available Phosphorus source
    5. Vitamin D to aid bone mobilisation & gut absorption
    6. Also contains Calcium to help maintain a correct Calcium : Phosphorus ratio.

Click HERE for more information or Call Us on 01772 690131 option 1

Related Products