Let's talk about calcium and bones!

[otto]

I use the bones from the meat I prepare for them for soup stock too. I save all the thigh bones from the turkey, chicken and cornish hen. When I have enough, (or when my existing freezer soup stock has been used up) I make another pot. But it's for me, not them.

And yes, I always simmer long enough to get that lovely aspic, too. Such healthy stuff, full of collagen and nutrition!

 

[bridget graham]

Funny, I was just going to start a new thread about chicken wings. Thank you so much for all of this information! I ordered a KitchenAid mixer with the meat grinder attachment but then I found out that it won't handle bones. Now I'm looking into alternate ways to feed them raw bones.

 

[aprilprey]

Hello Folks!

Today The Boyfriend and I set out to make our biggest batch yet - but wanted to confirm how much chicken bone to leave in.  The Boyfriend, being a stickler for data and details, starts crunching numbers to get something more specific than Dr. Pierson's "remove 20%-25% of thigh bones"....

Well, suffice to say, we went down the same rabbit hole of looking for a credible source of mineral analysis of chicken bones that many of you have (and the chicken is still sitting in the fridge)!  I'll spare you the gory details, the calculations, the arguing.  BUT - in the course of our web surfing, I did find a PDF of a study done in Thailand on extracting calcium from chicken bones to use as a supplement.  At the end of the paper, there is an analysis of chicken bones - see page 9 "Results: chemical composition of raw material" - the raw material being chicken bones.

http://www.aseanfood.info/Articles/11016100.pdf

The numbers they come up with are:

5.5% calcium in chicken bones (by weight, wet basis)

2.6% phosphorus in chicken bones (by weight, wet basis)

This is a lot lower than another source we are plugging into a spreadsheet - a forum where a member had researched and based her figures primarily on human bones:

http://www.catforum.com/forum/62-raw-food-diet/127884-chicken-bones-7.html#post740494

This source states:

19% calcium in "bone" (human) by weight

9% calcium in "bone" (human) by weight

Anyhow, I think we have finally devised a spreadsheet to take all calcium and phosphorus from all ingredients in Dr. Pierson's recipe to help us achieve close to 1.2:1 calciumhosphorus.

Whew.  Now to put that kind of effort into our OWN diet....

 

[mschauer]

I'd be careful about assuming those values hold true for all chicken bones. They may be OK to use as an average for an entire chicken skeleton but individual bones will vary by a lot. Weight bearing bones are more mineral dense than non weight bearing bones for instance. Even as an average for the entire skeleton they may be questionable. The age of the chickens and how they are raised will affect bone density. That study used chickens raised in Thailand which may or may not be representative of chickens in the US. 

You should also consider that they used a deboning machine which you aren't likely to be using Did you see this in the Discussion section (my added bold):

This study reported the nutrient composition in chicken bones from one slaughter plant of Laemthong Product Co., Ltd. However, moisture, protein, fat and calcium concentration in chicken bones from other slaughter plants may be different due to the efficiency of the deboning machines in each plant.

Frankly I wouldn't be comfortable using those values just based on that study. 

 

[aprilprey]

We aren't - we are working with the lower numbers and the higher ones; will probably use something in between - especially since thigh bones are weight bearing and I agree would have more calcium.  There do seem to be more sites quoting higher numbers as well. And I did come across a slew of articles on the effect the calciumhosphorus feed itself has on chickens too, so that's pretty clear evidence that its tough to pin down one number (and who knows what chickens eat in Thailand?).  But - don't bird have lighter bones than mammals - that's one thing that keeps bugging me which is why I think that lower end should at least be looked at.  I think I'll track down a book on the biology of bones - that's the source of info one forum poster had used.

Curious to know: has anyone ever contacted their country's "Chicken Board"?  I am sure it goes by different names in different places, but you know what I mean.  I might contact the US group sometime this week, all those chicken feed studies have got to have come up with something.  It is frustrating that in this age of all this information, that bit of info is so hard to come by.  Why are the dimensions of Jennifer Aniston's body easier to come up with than the composition of chicken bones?
 

 

[mschauer]

We aren't - we are working with the lower numbers and the higher ones; will probably use something in between

My point was that the value of those numbers for any use is pretty questionable in my opinion. The Ca requires having a pretty good idea what the calcium and phosphorus content is. It is pretty useless otherwise.
Is it really hard to believe that people care more about Jennifer Aniston's body than they do about chicken bones? 

I've found studies that include the calcium content of various chicken bones but there was always something about the bones or the study that made the results unusable for our purposes. What we need to know is the average composition of the various chicken parts we buy at the store. That isn't something that anyone is likely to focus on or include in a study.

Keep looking. The information may be out there just waiting for you!

 

[aprilprey]

You only have to play with the lower number (5.5) a little bit before you notice its "off" somehow - you'd have to add a crazy amount of bone - so I do agree with you - it sure doesn't work for thigh bones.  It at least it confirms that Dr. Pierson's estimate has a sound basis - I can't find a place on her site where she gives anything more specific than "remove 20%-25% of the bones" - I wish she would at least note what she's basing that on outside of her own experience (maybe there is a reason she does not).  Her info is a little scattered - every time I read it I find something I had forgotten!  I feel more comfortable (using the higher numbers) calculating how much meat and bone I need by weight, rather than counting them and estimating.  ETA: It must be the soapmaking - I am used to very precise weighing and percentage calculations.  I can't stand estimating - I need target numbers, data and a trusty scale, otherwise, it just feels sloppy.

AND - I did come across the process to extract the calcium at home using lye (NaOH) which god knows I have a ton of as a soapmaker! If only I had a real lab beaker sitting around here...

Interesting though, that calcium amounts can vary THAT much. I am wondering if that Thai study used primarily necks and backs.  If you look at Karen Becker's grind-in-the-bone recipes, she uses chicken backs.  The amount, by weight, is quite high - 4.5 lbs of chicken backs for 5 lbs of meat or so (muscle, heart) - very similar to what I get playing around with the lower 5.5% with similar numbers resulting.  Way more back/neck bone based on weight than thigh bones - and the calcium ratio of that recipe, without supplements, is very similar to what I am getting on the spreadsheet.

 

[mschauer]

Questions and inconsistencies like those are *exactly* the reason I gave up trying to use whole bone. It was making me crazy. I came to the conclusion that the only way I could really know how much calcium and phosphorus is in my food was to use a supplement. I use MCHA (freeze dried bovine bone) because I was able to get a fairly complete nutritional analysis of it from the manufacturer. 

And I also wish Dr. P would include more information on the "whys" of what she suggests.

And I also noticed that the amount of chicken backs in Dr. Beckers book recipe seems way too high. 

Like I said, it all just made me crazy! 

 

[mschauer]

Interesting though, that calcium amounts can vary THAT much. I am wondering if that Thai study used primarily necks and backs.  If you look at Karen Becker's grind-in-the-bone recipes, she uses chicken backs.  The amount, by weight, is quite high - 4.5 lbs of chicken backs for 5 lbs of meat or so (muscle, heart) - very similar to what I get playing around with the lower 5.5% with similar numbers resulting.  Way more back/neck bone based on weight than thigh bones - and the calcium ratio of that recipe, without supplements, is very similar to what I am getting on the spreadsheet.

You do understand that the 5.5% calcium value referred to in the study isn't 5.5% of bone but rather is 5.5% of the output from a deboning machine? Deboning machines aren't 100% efficient. What comes out is bone with other stuff clinging to it. That's why this statement from the study is significant:

This study reported the nutrient composition in chicken bones from one slaughter plant of Laemthong Product Co., Ltd. However, moisture, protein, fat and calcium concentration in chicken bones from other slaughter plants may be different due to the efficiency of the deboning machines in each plant.

 

[aprilprey]

Just found another research paper (also Thailand) that notes 28%-32% (chicken and fish) calcium.  Wow, they really have problems with calcium in Thailand I guess...trying to mine those bones for supplements!

http://rdo.psu.ac.th/sjst/journal/28-2/11_calcium_source.pdf

I called the Chicken Council in Washington DC.  Freaking lobbyists too busy lobbying - they only take messages.

I see what you mean though - when we run out of taurine tablets and we have to buy more supplements anyhow - There Will Be a Reckoning!

I used to be a paralegal, have a reputation for finding obscure legal memos that nobody else could find.  Now I am obsessed with finding this data, which I know is out there it's probably in some aggie/farm newsletter somewhere sitting on a chicken farmer's desk.

 

[aprilprey]

Oh yeah, the entire thing was picked apart so we did see the flaws - which is why its "notable but not going to be a big factor".  See the second paper I posted...much longer and a bit more in depth with higher numbers, goes into fish as well.  Darn charts are hard to read though.

 

[mschauer]

I used to be a paralegal, have a reputation for finding obscure legal memos that nobody else could find.  Now I am obsessed with finding this data, which I know is out there it's probably in some aggie/farm newsletter somewhere sitting on a chicken farmer's desk.

It was a topic I was obsessed with for a while also. I got over it. 

For a long time (years) there was what was claimed to be the laboratory analyses of several chicken pieces (back, neck, etc) posted at a raw feeding web site. The analyses included calcium and phosphorus content. I saw an inconsistency in that the analysis implied that a chicken wing has a higher meat to bone ratio than a chicken breast. I tried for a long time to convince myself that the analysis was correct but I just didn't believe it. That inconsistency put all of the analyses in question as far as I was concerned. The analyses were finally taken down a year or so ago. Considering how useful they would have been to raw feeders if accurate I assume they were taken down because they were found to be inaccurate. I just mention that as a warning to view whatever you find with a healthy dose of skepticism. Definitely consider the source.

 

[aprilprey]

May I ask which 12-Step Program you used to get over it? LOL. I think The Boyfriend is even worse, being a mechanical engineer.  He's used to having COPIOUS, peer-reviewed, time-tested information on any and all materials he might be dealing with - down to the most obscure and rare.  He might need more aggressive therapy - maybe electroshock?

In the end, we deferred to Dr. Pierson's 10 years of actual experience with the recipe.  Except, I refused to use her "just count the thighs and debone 20%"; all thighs were deboned so I could weigh out the bone and take out 20% based on weight.

Well, just to be a Masochist - I plugged in the final bone weight, meat weight - into the first SS using the 5.5% calcium (the lower amount).

Well - knock me over with a feather - darned if it did not come out to a nice 1.22:1  calciumhosphorus ratio.  Note: we designed it to take into account calcium and phosphorus from all sources in the recipe, including the liver and egg.  That's another Grrrrrr moment there - she comes right out and says there is no phosphorus in eggs but a simple Google search finds that to not be true at all!

This does strengthen my resolve to keep a little high quality canned in the mix - that's how I'm achieving variety.  Weruva has tons of info on their food, so at least I can confirm they have it right.
 

 

[mschauer]

Well, just to be a Masochist - I plugged in the final bone weight, meat weight - into the first SS using the 5.5% calcium (the lower amount).

Well - knock me over with a feather - darned if it did not come out to a nice 1.22:1  calciumhosphorus ratio.

But you do realize that calculation is essential meaningless given where the 5.5 value came from? If all you want is a value that when used to calculate the Ca will result in a ratio that you want or expect it is easily derived. If on the other hand what you want is a value that reasonably accurately represents the calcium content of your food that is another matter. In my opinion it is more than a bit of a stretch to assume that the calcium content of the output of a deboning machine with its indeterminate inputs and outputs is reasonably representative of the calcium content of a chicken thigh bone.

 

[lcat4]

Aprilprey, I think it's great you have a partner in this raw food process. My engineering background husband has let me, a non-science person, take this on solo, with the overall guiding words of "just don't kill the cats". So far, so good! I do appreciate the partnership of the TCS community to help get this right.

 

[aprilprey]

Aprilprey, I think it's great you have a partner in this raw food process. My engineering background husband has let me, a non-science person, take this on solo, with the overall guiding words of "just don't kill the cats". So far, so good!

I do appreciate the partnership of the TCS community to help get this right.

LOL - it goes both ways.  It both helps AND provides more stress - we don't always agree on how to do this.

 

[aprilprey]

But you do realize that calculation is essential meaningless given where the 5.5 value came from? If all you want is a value that when used to calculate the Ca will result in a ratio that you want or expect it is easily derived. If on the other hand what you want is a value that reasonably accurately represents the calcium content of your food that is another matter. In my opinion it is more than a bit of a stretch to assume that the calcium content of the output of a deboning machine with its indeterminate inputs and outputs is reasonably representative of the calcium content of a chicken thigh bone.

True that - but: had we never even tried to figure this out like obsessed crazy people, we would have done what we ended up doing anyway: following Dr. Pierson's guidelines and removing 20% of the bone.  Its what we have done all along (this is batch #5), basically follow a "faith based" path that since the results work for her for 10 years - we'll go with that.  The fact that I happened to get good numbers is, well - why? I am not sure since there is so much variable information. Maybe the calcium content of that many bones from different birds varies so much that even if you did have one good number, it still would not work plugged into a formula, but comes out to a healthy balance in the end?  She does make pretty large batches, so I wondered if that had anything to do with it.  But it would be impossible to calculate - you'd have to know the content of each bone.

I am chalking it up to "puzzling" rather than "well that proves that".  My rushed/tired at that point post may not have expressed that well enough, so I want to emphasis that.  Stream of consciousness posting - my bad.  But the "remove 20%" works for her and I am assuming (and hope it not misplaced faith) she, being a vet, would recognize any long term effects.  She does give the impression she has been very closely observant of the effects of the diet over the years. 

Jeez, I hope we don't ever go to her site some day  to find: "WAIT, stop - everything I said was wrong!" 

 

[mschauer]

Originally Posted by aprilprey  

Jeez, I hope we don't ever go to her site some day  to find: "WAIT, stop - everything I said was wrong!" 

I think that is highly unlikely after her 10 years of experience feeding the food. 

 

[aprilprey]

I think that is highly unlikely after her 10 years of experience feeding the food. 

Thanks for saying that - I am still pissed and slightly distrustful since my own vet prescribed Science Diet!

 

[nessakhoo]

Hi guys sorry to hijack

Why is it when ever dog raw, there's always pure eggshell.

Can't we do the same for cats? Is there a need to make it into a powder?