Let's talk about calcium and bones!

[ldg]

Because it's such an important subject, when peaches08 asked this question in another thread, I thought it made sense to give it its own thread.

Are there any nutritional benefits to using eggshell calcium or MCHA? Please forgive me if this has been answered before.

Calcium options for raw feeders:

Fresh bone-in meals
Bone meal
MCHA - microcrystalline calcium hydroxyapatite (freeze dried bone)
eggshells / eggshell powder (which is 97% calcium carbonate of which 39% is elemental calcium)
other forms of calcium carbonate - usually some kind of fish shell, I think.

MCHA is just freeze dried bone, so I don't know if there's a nutritional difference between feeding fresh bone or MCHA, because I don't know if the MCHA contains the marrow or not. :dk: But for those feeding PMR as opposed to ground, the guideline for cats is to not feed structural bones anyway, so I'm not sure how much marrow actually gets fed. One difference certainly would be bioavailability (ground to a fine powder being much more bioavailable).

For FLUTD kitties, eggshell has less magnesium than bone; and for kitties with impaired renal function (CRF or CKD), eggshells have essentially no phosphorus. Fresh bones have roughly twice as much calcium as phosphorus (5 parts calcium to 3 parts phosphorus is more like it I think) - but they have a lot of phosphorus. None of my cats, to my knowledge, have kidney problems. But most of them are seniors at this point. Maybe feeding them a lower phos diet than they'd get with meat and bone will help prevent it? :dk: Of course, African wildcats live on average to be 15 years old... no idea how much bone vs eggshell they eat. I just know they're eating mostly small rodents and lizards, maybe some birds, not factory farmed chickens, ground llama, lamb, etc.

Personally, I believe in variety in everything. So I feed my cats fresh whole bone via whole quail & a number of parts of cornish hen, rabbit ribs, and chicken wingettes and wing tips; I feed four meals a week of ground whole animal, so they get ground bone; I also feed them eggshell and MCHA as the calcium source, switching up every two weeks. One of the reasons I use eggshell and MCHA, in addition to the variety factor, is that I prefer to have a tighter reign on the Ca ratio than I can get feeding just bone, or using just ground pre-mix / whole animal. I expect cats would eat eggs in the wild - the shells likely have trace minerals in different amounts than those found in bone.

We all see the benefits to feeding fresh bone as re: dental health. But in the "food for thought" category, here's an interesting discussion: http://www.petmd.com/dog/nutrition/...ts_of_bone_composition?page=show#.UdCA-T5fkyd

...and an interesting blog from pet-grub, the same blogger I complained wrote a very confusing discussion of the Ca ratio. I totally do not agree with the Ca ratio of 2:1, though it seems this person is discussing dogs, not cats, and perhaps they have a higher Ca ratio requirement than cats. But she makes the same point: in nature, animals eat a variety of calcium sources. http://www.pet-grub.com/whats_new_pussy_cat/bones_are_not_the_best_source_calcium_for_dogs_and_cats

A nutritional profile of eggshell:

http://www.afn.org/~poultry/flkman4.htm
Short version: http://www.poultryindustrycouncil.ca/pdfs/factsheets/fs_133.pdf

Duck eggs vs chicken eggs: http://www.ajas.info/Editor/manuscript/upload/16_44.pdf


Nutritional profile of bone:

Chemical composition of chicken bone (not detail, only macro) : http://www.agriculturejournals.cz/publicFiles/08103.pdf

I'm sure there are a million links one could use here. But the PetMD blog had a good summary (repeat of link above): http://www.petmd.com/dog/nutrition/...ts_of_bone_composition?page=show#.UdCA-T5fkyd

Bone material properties: (Scroll down to the section) http://depts.washington.edu/bonebio/ASBMRed/structure.html

Composition of bone: http://www.doitpoms.ac.uk/tlplib/bones/structure.php


Research on MCHA (though the nutritional profile should be the same as young bovine bone):

http://seniorhealthcare.co.nz/index.php?page=Calcium Research
http://www.oralchelation.com/technical/calcium2.htm


And bones from a PMR feeding perspective: http://catcentric.org/nutrition-and-food/raw-feeding/dem-bones-dem-bones-dem-scary-bones/

Finally, because this is about bones and calcium, I found this great table indicating the skin, meat, fat and bone content of various chicken parts: http://www.abyssiniancats.info/bonesinchickens.php

I have NO idea if that answered your question or not. :lol3: But I'd love others input, links and thoughts.

 

[katluver4life]

I'm still new to raw. I recently switched my 3 to raw using a meat/bone/organ grind with the Alnutrin supplement for meat with bone. So no added calcium added obviously. Taken from the site pet-grub, this comment sent me into a panic:

Question: Is bone–in chicken ground in a meat grinder a good source of calcium, iron and potassium?

Answer:  Unfortunately, all bone is high in phosphorus and so when you feed meat and bones, you are still getting more phosphorus than calcium.

Bones should be considered a mineral supplement, not a calcium supplement.

So have I been depriving them of enough calcium? I have already started to put a new order together for just some ground meats and using the supplement of COTW or Alnutrin with calcium in their rotation, but that won't go in for another week or so.

 

[ldg]

The petgrub site is an opinion blog. I do think whole animal ground food may be a bit bone heavy, but I doubt outside of acceptable Ca ratios as many people have cats and dogs eating just those for a long time.

Spooky prefers ground, and if I give her only that, she gets constipated. (I use rabbit, llama, goat, and pork).

But ALL bone has more calcium than phosphorus. The chicken bone study indicates that it is almost twice as much calcium as phosphorus, which is what it is for the NOW calcium hydroxyapatite I use. So yes, your kitties are getting plenty of calcium, and probably a Ca ratio closer to the higher end of acceptable rather than the low-end of acceptable.

mschauer has done more research on bone. Hopefully she'll weigh in!

 

[carolina]

That's a weird comment..... Where did that come from? Of course Bone is a source of Calcium..... That's why it is so essential in feeding raw. It does have phosphorous, but not more than Calcium - it is in the diet to balance the Phosphorous content in the meat, and it works well.

Please, don't add Calcium to a bone in diet unless you feed a mixed diet - one day a ground bone-in meal, another day you feed meals balanced with Alnutrin with Ca., another balance with COTW.... But you do NOT need to add Calcium to a bone-in diet. There is nothing wrong with variety.... As you can see, Laurie (LDG, does just that)

Be very careful before you do what you are thinking about doing, you can throw your entire diet out of balance.....

As long as you have 80% meat about 10% bones (some people do a little less, like 7 or so), 5% liver and 5% another secreting organ you are ok. Don't top the Calcium off

 

[katluver4life]

That's a weird comment..... Where did that come from? Of course Bone is a source of Calcium..... That's why it is so essential in feeding raw. It does have phosphorous, but not more than Calcium - it is in the diet to balance the Phosphorous content in the meat, and it works well.

Please, don't add Calcium to a bone in diet unless you feed a mixed diet - one day a ground bone-in meal, another day you feed meals balanced with Alnutrin with Ca., another balance with COTW.... But you do NOT need to add Calcium to a bone-in diet. There is nothing wrong with variety.... As you can see, Laurie (LDG, does just that)

Be very careful before you do what you are thinking about doing, you can throw your entire diet out of balance.....

As long as you have 80% meat about 10% bones (some people do a little less, like 7 or so), 5% liver and 5% another secreting organ you are ok. Don't top the Calcium off

That comment was from the site http://www.pet-grub.com/holistic_pe...s_a_good_source_of_calcium_iron_and_potassium

I wasn't going to add calcium to their meat/bone/organ grind (which is from Hare Today), but rather mix up their variety and adding a meat only ground with either COTW or the alnutrin with calcium to be sure they got their needed calcium. Reading that blog threw me into a panic thinking they were not getting the calcium they needed from the bone in grinds alone.

@LDG Thank you for easing my mind.

I'd rather they be on the high end of the Ca ratio then the low. They have no issues handling it and actually still have stools daily.

 

[ldg]

I debated about whether or not to include that link. The only reason I did was for the point as re: variety, which most raw feeders don't provide when it comes to calcium. And it's certainly not essential to provide variety in calcium sources, certainly not in the same way it is important to provide variety in proteins.

But this does bring up an important issue, especially since the same blog, which cites no research or sources, caused so much confusion in another thread (Mixing raw with dry) just the other day: base your diet choices on reliable, researched, responsible information and data, not opinion. :nod:

The blog author provides no data in proferring that opinion, therefore, IMO, it can't be taken seriously. Her point about variety makes logical sense (to me). But we know from a well-researched site written by a vet that chicken bone provides the calcium (and trace minerals) that cats need. (Dr. Pierson, catinfo.org). She provides a recipe for ground that has sustained and maintained healthy cats on a raw diet of chicken and chicken thigh bone for ... over a decade? That, to me, is a more reliable source. :nod:

 

[carolina]

I debated about whether or not to include that link. The only reason I did was for the point as re: variety, which most raw feeders don't provide when it comes to calcium. And it's certainly not essential to provide variety in calcium sources, certainly not in the same way it is important to provide variety in proteins.

But this does bring up an important issue, especially since the same blog, which cites no research or sources, caused so much confusion in another thread (Mixing raw with dry) just the other day: base your diet choices on reliable, researched, responsible information and data, not opinion. :nod:

The blog author provides no data in proferring that opinion, therefore, IMO, it can't be taken seriously. Her point about variety makes logical sense (to me). But we know from a well-researched site written by a vet that chicken bone provides the calcium (and trace minerals) that cats need. (Dr. Pierson, catinfo.org). She provides a recipe for ground that has sustained and maintained healthy cats on a raw diet of chicken and chicken thigh bone for ... over a decade? That, to me, is a more reliable source. :nod:

Sorry you were thrown in a panic

 

[katluver4life]

After reading that blog, I did in fact return to look at Dr. Piersons recipes for her bone in diet and of course found that she too felt the bone was certainly enough calcium. Just confused the hell out of me.

  Which is why I come here! 

@Caroline&LDG

 

[tammyp]

I don't know if this will post, but it is a handy % bone in chicken picture.  

I just want one for rabbit!!

 

[furmonster mom]

Gorram it if I can't remember where I saw it now, but I seem to recall that there is a triumvirate relationship with Ca, P, & Mg.  I know all three are important to bone health and that all three are found in bones. I just can't remember how they interact/relate to each other.

*grumble grumble* getting old *grumble*

 

[mschauer]

Gorram it if I can't remember where I saw it now, but I seem to recall that there is a triumvirate relationship with Ca, P, & Mg.  I know all three are important to bone health and that all three are found in bones. I just can't remember how they interact/relate to each other.

This is a good introduction to what I'd like to discuss with regards to this issue.

I actually agree that bone is a poor calcium supplement. But what we are looking for when creating a homemade cat food isn't really a calcium supplement. What we are looking for is a bone substitute. We are trying to create a food modeled on a mouse and a mouse has bone from which a cat derives calcium and other nutrients. 

We know from human nutrition that is is best if nutrients are consumed in their natural, unprocessed, form. Not only can processing damage nutrients but science is starting to understand the importance of consuming some nutrients at the same time and in the same quantities as they naturally occur. We know, for instance, that calcium is better utilized by the body when it is consumed with vitamin D. We don't, however, have any where near a complete understanding of human nutrition much less feline nutrition. The more we provide nutrients in an unnatural form the more likely we are providing them in a less than optimal manner just because of things we don't know.

In my opinion the biggest difference and the biggest advantage of creating our own cat food rather than buying commericial processed foods is that we can control the extent to which nutrients are provided in their natural form. The closer we come to this objective the closer we are to actually recreating a mouse and the less nutritional unknowns are a factor.

As to the assertion in the PetMD link that bone is essentially just calcium and phosphorus here is a partial nutrient profile of MCHA (per 100 g) :

calories         124

saturated fat    400 mg

protein           25 g

carbohydrates    3.7 g

sodium           600 mg

iron             390 mcg

calcium          26 g

phosphorus       12 g

magnesium        400 mg

amino acids: 

aspartic, glutamic ,hydroxyproline, serine, arginine, threonine,

glycine, alanine, proline, valine, methionine, isoleucine, leucine, phenylalanine,

hydroxylysine, lysine, histidine, tyrosine

There are other minerals in trace amounts also.

Laurie, the protein, fat and amino acid content leads me to believe the marrow is included although I can't say that is definative proof. 

From the human studies that have found the calcium provided by MCHA to be better absorbed by humans the speculation is that there is something about the total bone matrix that aides in absorption and utilization.

I know of no evidence that there is any harm in using something like calcium carbonate (eggshell) to provide the calcium in our pet food. Using bone or MCHA is just a more natural way to provide it which may or may not matter.

Edit : Corrected math error in converting nutrient values from per g to per 100 g.  

 

[carolina]

I know a year is nothing in the matters of things..... But I know that it is time enough for a cat to show signs of nutrient deficiencies.
My cats have been eating a raw diet balanced with eggshells for almost 1 1/2 yr and are all doing fantastic.

Don't know if that matters to anyone, but just want to throw it in the mix.

 

[mschauer]

I seriously doubt any nutritional deficiency would ever result from using a calcium source other than bone. The benefits, if any, of using bone would most likely be relatively minor. Really it isn't a question of whether not using bone will result in a deficiency. I don't think any one believes it will.

 

[furmonster mom]

So after spending several hours searching ...

"calcium magnesium phosphorus"

"calcium magnesium"

"calcium phosphorus"

"magnesium phosphorus"

"calcium magnesium phosphorus ratio in bone"

"calcium magnesium ratio"

"magnesium ratio in bone"

"magnesium ratio in body"

"magnesium percentage in body"

... and half a dozen more phrases that I can't remember.... There was one article that summed up all the bits and pieces in a fairly (quick & dirty) comprehensive way:  Mineral Balance: Calcium-Magnesium-Phosphorus

Here are a few more... a little more difficult to parse, especially since many of them focus on the calcium requirement for children:

Magnesium

Kidney Journals (oxford)

Phosphorus (NAP)

Magnesium (NAP)

Bone Health for Horses

MCPB for bone regeneration (I just thought this one was really interesting)

Basically, even though Mg is relatively low when looking at the overall ratio, it is actually one of the really important minerals in our bodies... and 60% of it is in bone, 25-30% in muscle, and the rest in other cells. 

While humans may get Mg through salts, nuts, grains and other plant sources, an obligate carnivore is limited to their prey... they must get all their nutrients from the bodies of their prey. 

When we try to imitate the natural diet of an obligate carnivore, we need to take into account every aspect of their prey's composition.  60% Mg is in the bones.  If we do not feed the bones, then we should look into other sources for the balance.  Good news is, Mg is processed through the kidneys, so I imagine they are a good source for the balance of that particular mineral. 

 

[mschauer]

That's for tracking down that information!

Looks like kidney isn't such a great source of Mg though. It only has 17 mg/100 g. Beef chuck has more at 22 mg/100 g. But then MCHA only has 4 mg/100 g. Hmm...

Made a math error. MCHA has 400 mg Mg/100g. I corrected my post above. 

 

[chevs]

This is a very timely discussion for me, since I have recently (like in the past week) had to stop feeding bones to one of my cats and need to supplement. I bought this Eggshellent eggshell powder, which recommends using 1 tsp to balance 1 pound of meat. But that would mean almost 1/4 tsp per meal and Seamus won't eat his food with that much powder on it. He'll happily do 1/8 tsp per meal. I think that should be enough, because that means he gets about 475 mg of calcium per day. How much eggshell do you use?

 

[ritz]

For FLUTD cats (not kittens), why is this important "eggshell has less magnesium than bone"?

Ritz has FLUTD and is prone to UTIs (crystals and bacterial).

 

[mschauer]

This is a very timely discussion for me, since I have recently (like in the past week) had to stop feeding bones to one of my cats and need to supplement. I bought this Eggshellent eggshell powder, which recommends using 1 tsp to balance 1 pound of meat. But that would mean almost 1/4 tsp per meal and Seamus won't eat his food with that much powder on it. He'll happily do 1/8 tsp per meal. I think that should be enough, because that means he gets about 475 mg of calcium per day. How much eggshell do you use?

Laurie (LDG) recently posted that she uses 1/32 tsp / oz meat and 3/64 tsp / oz organs.

 

[mschauer]

For FLUTD cats (not kittens), why is this important "eggshell has less magnesium than bone"?

Ritz has FLUTD and is prone to UTIs (crystals and bacterial).

Magnesium is one of the components of struvite crystals. I'm pretty sure the idea of limiting the minerals that compose the crystals is an outdated way of thinking. This issue may illustrate why that is. Magnesium is an important element to a cats diet. The current thinking on how to prevent the crystals is to adjust the diet to result in more acid urine and increase water intake. A raw diet usually results in urine acidic enough to prevent the crystals. In fact, that is why I switched to a raw diet. My Jeta is prone to struvite crystals. 

 

[mrsgreenjeens]

This is a very timely discussion for me, since I have recently (like in the past week) had to stop feeding bones to one of my cats and need to supplement. I bought this Eggshellent eggshell powder, which recommends using 1 tsp to balance 1 pound of meat. But that would mean almost 1/4 tsp per meal and Seamus won't eat his food with that much powder on it. He'll happily do 1/8 tsp per meal. I think that should be enough, because that means he gets about 475 mg of calcium per day. How much eggshell do you use?

If I am reading you correctly, this means Seamus is eating 12 oz per day?????? (Well, I'm basing that on figuring 3 meals per day, 1/4 teas for 4 oz)  That's a whole lot of raw food per day.  Is he a kitten? 

Anyway, since Darko doesn't like powdered anything on his food, I simply mix the powders with the meat juice (or water if not enough juice) and then make sure I coat all his meat strips in the juice.  Then he licks his bowl clean.  Easy Peasy