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As can be seen in the table below most animal foods do not contain an optimal calcium / phosphorus ratio - Our attention should be directed to    correcting a potential imbalance.

Remember: you cannot correct a calcium deficiency with any source of bone meal, you must use a source that has little or no percentage of phosphorus, such as cc781905-5cde-3194-bb3b-136bad5cf58d_ calcium carbonate, calcium lactate, gluconate of football.

There are many different opinions on what the ideal Ca: P ratio should be, but I think it is reasonable to recommend a ratio  between 1.0 and 1.3 parts of calcium to 1 part of phosphorus. Unfortunately, it may be very difficult to manage this relationship with the BARF or Whole prey, as the report _cc781905-5cde-3194-bb3b_bad5cf5c5-3194-bb3b-136bcc7-136bcc7 which might 136bad5cf58d_be adequate for younger cats, may not be adequate for older cats ....
If necessary, it is easier to calculate the Ca: P ratio more precisely  in diets without bone supply.

To achieve the above recommended ratio, you need to add 1000 mg of calcium   (approximately 3 grams of eggshell powder) to 1 kg of raw boneless meat ._cc781905-5cde-3194- bb3b-136bad5cf58d_


Calcium Supplements

by Ch. M. Ruessheim

updated: July 2, 2002


Calcium supplements come in several forms (calcium salts), but only part of the calcium salt is elemental calcium. It is important to know how much elemental calcium a supplement provides because all the dietary recommendations refer to elemental calcium. To calculate how much elemental calcium is in a supplement, multiply the total milligrams (mg) by the fraction of elemental calcium to get total mg of elemental calcium. See examples below:

Calcium carbonate: = 40% elemental calcium
Example: 500 mg calcium carbonate x 0.40 = 200 mg elemental calcium

Calcium citrate: = 21% elemental calcium
Example: 500 mg calcium citrate x 0.21 = 105 mg elemental calcium

Calcium lactate:   = 13% elemental calcium
Example: 500 mg of calcium lactate x 0.13 = 65 mg elemental calcium

Calcium gluconate: = 9% elemental calcium
Example: 500 mg of calcium gluconate x 0.09 = 45 mg elemental calcium

Dicalcium phosphate:   = 23% elemental calcium + 19% phosphorus *
Example: 500 mg of dicalcium phosphate x 0.23 = 115 mg calcium + 95 mg phosphorus
* Helmut Meyer / Jürgen Zentek give different values: 21/16

Egg shells:   = 36-37% elemental calcium + traces of phosphorus and trace elements
Example: 500 mg of dried powdered eggshell = ca. 180 mg elemental calcium

Bone meal: _cc781905-5cde-3194-bb3b-136bad5cf58d _ = _ cc781905-5cde-3194-bb3b-136bad5cf58d_ 30% elemental calcium + 17% phosphorus
Example: 500 mg of bone meal x 0.30 = 150 mg elemental calcium + 85 mg phosphorus
Important: Different products have different calcium / phosphorus contents! Check the label!
Notes: The use of bone meal as a calcium supplement for raw meat diet may not be
warranted for animals with diminished kidney function due to additional phosphorus content.


Some other measures:

1 teaspoon of bone meal = 4 g
1 teaspoon of calcium lactate = 3.5 g
1 teaspoon of calcium carbonate = 2.0 g
1 teaspoon of eggshell = 5 g
1 teaspoon of  Kitty Bloom Kalac M34   (38-39%) = 5g 
1 teaspoon of  Animal Essentials Calcium Supplemen t (34%) = 3g
100g chicken neck = approx. 800 mg calcium, 500 mg phosphorus, 100 mg sodium
100g chicken feet = approx. 2130 mg calcium, 770 mg phosphorus, 125 mg sodium
1 large eggshell = approx. 6 g = approx. 2200 mg calcium

Calcium / Phosphor Calculator  in english

Calcium / Phosphor Calculator  in deutsch

Very useful tool as you can vary meat type, Ca: P ratio as well as calcium / phosphor content of supplement used.

The Nutritional Aspects of Bone Composition

Mineral Content in Bones of Ostrich  (Struthio camelus var. Domesticus)

41.2% Calcium (36.3-45.7%)
16.8% Phosphorus (15.2-18.4%)
Ca: P ratio: 2.45: 1
0.49% Magnesium (0.35 - = .64%)
167 mg Zink (93-287 mg)
94 mg  Iron (42-195 mg)
8.5 mg Copper (3.3-14.9 mg)
8.3 mg Manganese (4.6-13.0 mg)
10.0 mg Lead (0.9-56.8 mg)
453 mg Fluoride (290-640 mg)
11.2 mg Aluminum (1.6-20.8 mg)

Mg values are per kg bone ash. 

Reference: Bissinger Klaus, Dissertation, University of Giessen, 2000 "Quantitativer Nachweis wichtiger Mengen- und Spurenelemente in Serum, Leber, Knochen und Vollblut sowie einige andere Gewebeparameter und Daten von gesunden, südafrikanischen domestic Farmstraussen (Struthio varachtus).

Mineral Content of Chicken Feet

Nutrient Composition of dried Eggshells

Carbonate vs. citrate

Composition of egg shells with adherence of albumen

adapted from Animal By-Product Processing & Utilization H.W. Ockerman, CL Hansen Values on DMB (except water & protein)

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