Let's talk about calcium and bones!

[lcat4]

Continuing the discussion of whether cats get enough Mg with eggshell, I rechecked my Alnutrin calculator sheets for the various meats. Taking only Alnutrin with eggshell, meat, 6% liver, and water, the lowest DM % was with beef at .05%, still meeting AAFCO minimum of .04%. The highest % of meat I feed was chicken thighs at .1%. I tend to feed more ground dark turkey and that is .09%.

From what I was reading, the requirement level for Mg is really dependent on the amount of Ca and P in the diet, as well as the pH of the urine. In an excerpt from Nutrtion for Cats and Dogs, I believe it said to look for canned foods with less than 1.2% Mg to protect against struvite issues, but again it's a pH issue.

In my boy cats' situation, I am trying to lower their P, thus using the eggshell. I'm also adding eggshell on the lower end of the Ca ratio (1.1:1) since my boys have higher blood calcium (although still in normal range). With lower Ca and P, not having as high of Mg should be okay (?).

My girls are rotating between the MCHA and eggshell mixes, and they are thriving.

 

[mschauer]

In my boy cats' situation, I am trying to lower their P, thus using the eggshell. I'm also adding eggshell on the lower end of the Ca ratio (1.1:1) since my boys have higher blood calcium (although still in normal range). With lower Ca and P, not having as high of Mg should be okay (?).

If you are going by AAFCO recommendations there is no reason to think otherwise. 

 

[lcat4]

And that is the million dollar question and lately the topic of many threads.

 

[mschauer]

For my part I do not discount the value of the AAFCO recommendations. When formulating a homemade diet I think it is essential to have some notion of whether what we feed our cats is nutritionally adequate. Comparing against the AAFCO recommendations provides that assurance. But, almost all commercial processed foods adhere to the AAFCO recommendations. Our homemade food has the potential to be better than those commercial foods not just because we use better quality ingredients but because we can use ingredients of our choice. We can use ingredients that we think will better approach the optimal diet for a cat.

As to the question of whether X amount of magnesium is adequate all we have to go on is the AAFCO recommendations. 

 In an excerpt from Nutrtion for Cats and Dogs, I believe it said to look for canned foods with less than 1.2% Mg to protect against struvite issues, but again it's a pH issue.

We discussed this in an earlier post. Limiting magnesium is an outdated approach to preventing struvite crystals.

 

[ldg]

Thanks for the info!

Another question: has anyone noticed any changes in blood calcium when switching from long term feeding of bone to just eggshell calcium? I'm curious since calcium carbonate isn't well absorbed by humans (hence we advise calcium citrate). I know that can be individual too.

I use 1/2 eggshell and 1/2 MCHA (basically), and current bloodwork doesn't show any change in bloodwork. The raw as a result of the higher protein they now eat shows higher BUN and creatinine in most of them, but still within normal ranges. Nothing else has changed.

 

[ldg]

Enjoying this discussion!  

One tiny bit of maybe useful info - magnesium supplements are recommended for humans to counteract the constipating effects of calcium supplements

I knew this, but had forgotten. Thanks for the reminder. This is very interesting... I wonder why Spooky gets constipated more easily when I use the MCHA or when she eats a lot of ground whole animal? :dk: Seems counterintuitive, when this aspect is considered. :scratch:

 

[ldg]

I certainly didn't mean to imply that anyone using eggshell was shortchanging Mg in the diet, or that they would run into any kind of deficiencies because of it.  Rather, I think that it's important to recognize the differences between bone and eggshell, and compensate accordingly if necessary.

I found another article about the mineral composition of eggshells, and conveniently there is a table (pg 3) showing the mg/g of each element:

Ca  387 - 401
Mg  3.5 - 4.5
P    .99 - 1.9

Not sure how it compares to bone exactly... maybe someone could lay them in a table side by side?
Unfortunately, I'm running on no sleep at the moment and it's finally catching up to me. 

If mschauer is up for it, maybe run the diet she has for my kitties with two different scenarios. One with all MCHA, one with all eggshell powder. Right now, it's set up as 1/2 eggshell and 1/2 MCHA.

And of course you included the magnesium in the eggshell in the analysis, mschauer, you're so thorough! :lol3:

 

[peaches08]

I knew this, but had forgotten. Thanks for the reminder. This is very interesting... I wonder why Spooky gets constipated more easily when I use the MCHA or when she eats a lot of ground whole animal? :dk: Seems counterintuitive, when this aspect is considered. :scratch:

Could it be the bioavailability of calcium in those vs. eggshell calcium?

Thanks for your answer about the bloodwork.

 

[ldg]

I don't think that would explain it, but I really don't know. I would think the lowest bioavailability of bone would be in the ground bone vs. the powdered eggshell or MCHA (which is also powdered). Of course, I don't know how much bone is in the ground whole animal. It could be more than the 6% - 10% PMR guideline. :dk:

Maybe it has something to do with the interaction of the phosphorus with the magnesium and calcium? :dk: Other minerals or nutrients in the bone? :dk:

 

[ldg]

...aaaand.... I'd to add to the discussion with a few more thoughts. :lol3:

While peaches08's original question was whether or not there are nutritional benefits to using eggshell or MCHA vs bone, my overall point with the thread was a general discussion of bones, raw feeding, and sources of calcium: general pros and cons, I guess.

mschauer put everything into perspective by pointing out

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.

...snipped a bit...

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.

And there are several points upon which I would like to elaborate.

1) Ultimately, our cats are not cats on their own, out in the wild - and many of them have come to us with imperfect GI systems, or have developed problems from eating highly processed, commercial cat food that doesn't have optimal (let alone species-appropriate) ingredients. For cats with issues, the advantage of a homemade diet is that we can control the inputs - and while for many raw feeders, the goal is to come as close to a "natural" diet as possible, it is the ability to tailor the inputs to the individual needs of our cats that can make a homemade diet so important. In the end, "optimal" changes with the needs of our individual cats.

And to that end, hopefully the discussion in this thread sheds some light on the different options that exist.

2) One thing we haven't included is plain old bone meal. That's likely because most of us participating here are already familiar with the drawbacks of bone meal, but for people new to the subject, here is the reason bone meal hasn't come up as an alternative: http://www.livestrong.com/article/543720-are-bone-meal-supplements-dangerous/ Bone meal, as opposed to MCHA, is a highly processed, heat-treated product. MCHA is freeze dried, not heat treated, and the NOW product (currently the only commercially available pure MCHA supplement available in the US) is made from young cows from New Zealand (so lower risk of heavy metals and other toxins due to age and feeding practices).

3) As mschauer has pointed out, raw feeders consistently hold up a cat's natural diet as being optimal. While cats as a breed are rodent specialists, they do eat much more than just mice. That is the reason some people feed their cats crickets, etc. And that that is part of the reason that I include some eggshell as part of the mineral source for my cats, having only one cat out of eight that seems to do better on the eggshell than actual bone, whatever form it's in.

 

[peaches08]

I don't think that would explain it, but I really don't know. I would think the lowest bioavailability of bone would be in the ground bone vs. the powdered eggshell or MCHA (which is also powdered). Of course, I don't know how much bone is in the ground whole animal. It could be more than the 6% - 10% PMR guideline. :dk:

Maybe it has something to do with the interaction of the phosphorus with the magnesium and calcium? :dk: Other minerals or nutrients in the bone? :dk:

I know Dr. Pierson recommends diluting ground rabbit with chicken thighs to reduce the bone and increase the fat, but I don't know any other grounds from HT.

Why bone is considered a bad source of calcium?

 

[ldg]

Why bone is considered a bad source of calcium?

Are you asking about bone meal, or mschauer's point about when feeding raw we're searching for "mouse bone" replacement, not a calcium substitute per se?

Because small bones, from chicken, rabbit, quail, etc. or ground bone are the most natural alternative when building a raw menu. If feeding ground, it doesn't much matter which bones are used, though like proteins from different animals and different parts of the same animal have different nutritional profiles, bones from different animals and different parts of the same animal have slightly different mineral and nutritional profiles.

...but if looking for *just* a source of calcium, bone comes with a lot of phosphorus, so the quantity of bone needed to balance the phosphorus in meat is higher than if using something that is mostly calcium.

So whether you're looking to develop a diet that is as natural as possible, or you're developing a specialized diet for specific need (like a kitty with CRF, for instance) makes a difference in what is "optimal."

 

[peaches08]

Yes, I was asking why bone was not a good supplement for calcium. I was thinking in terms of a cat with no health conditions. Bone meal? I can't say that I'm a fan.

I was also thinking of some cultures in which bone is the main source of calcium for humans.

As far as bones from specific parts of the body, I like using chicken thigh bones because of the marrow. I remember when I first started raw feeding I had to debone all the thighs and add premix to it (grinder was on backorder). My cats would scream and knock over the garbage can to get to the bones I was throwing away, so I gave in and just gave them to them. I know, not a good practice! In any case all 3 could bust open the thighs with their jaws without a lot of effort and I swear it was the marrow they were after because that's the end of the bone they ate and left the rest, all while pestering me for more. Once the grinder came in, they totally quit bugging me. This is what led me to ask why some folks use the calcium source(s) that they use. Other than health condition which require reduced phosphorus, and etc.

 

[furmonster mom]

My cats would scream and knock over the garbage can to get to the bones I was throwing away, so I gave in and just gave them to them. I know, not a good practice! In any case all 3 could bust open the thighs with their jaws without a lot of effort and I swear it was the marrow they were after because that's the end of the bone they ate and left the rest...

lol   I can totally picture that! 

Reminds me of one Thanksgiving when our friend was about to toss the turkey carcass into the garbage... I spontaneously yelled "Noooo!", and grabbed for it.  Everyone stopped and stared, "soup," I said sheepishly.

I've given the whole wings to my cats for several years, wing, drumette, and tips, never deboned them.  Why would it be considered "bad practice"?  The boys seem to have better jaw strength, so they get the drumettes.  Sometimes the middle is left untouched, but not often.  The girls handle both the bones in the wings just fine.  Our oldest, going on 18, gets the smaller ribs and tips, sometimes smashed and chopped by yours truly.

 

[ldg]

Hey, if they can crunch them, go for it! I just don't recommend people start there, especially if they're not already sure about the health of their cats' teeth. :nod: Most of my cats won't even eat large chunks of meat yet. :lol3: But I didn't start feeding raw until most of them were almost 10 years old.

 

[mrsgreenjeens]

Just have to ask...is mine the only head spinning about now

SO much information...brain on overload

 

[aprilprey]

Just have to ask...is mine the only head spinning about now

SO much information...brain on overload

Me too, but that just makes me more attracted to the "Lazy" method of just using the bone!  I like the KISS principle - its applicable to so many things.

 

[peaches08]

LOL at "soup"!

I say "bad practice" because somewhere I read that they shouldn't have bones that big...something about their teeth. One of Gadget's canines has a broken off tip, but I don't know if I got him that way, or if it happened while breaking bones, or what.

 

[otto]

Just have to ask...is mine the only head spinning about now :lol3:

SO much information...brain on overload

No yours isn't the only one. I'm saving the thread so I can take it in smaller doses. (the same way I do Dr Pierson's site :lol3

 

[ldg]

[ATTACHMENT=386]Chicken Bone.jpg (73k. jpg file)[/ATTACHMENT]
I don't know if this will post, but it is a handy % bone in chicken picture.  

I just want one for rabbit!!

Sorry, I keep meaning to ask - do you know where this comes from? It's a great graphic, but I'd love to be able to tell people the source.