Aafco And Home-made Food

[prairiepanda]

I know most people don't really bother looking at AAFCO recommendations when it comes to home-made recipes, but I did up an AAFCO recipe calculator to try and prove to my vet that my recipes are nutritionally complete. For the most part, it worked out fine. Playing around with it, I learned some interesting things about the formulations of commercial foods using veggies/grains/etc. and also found that horribly imbalanced foods can easily meet AAFCO standards since the majority of nutrients have no max values, nutrient ratios are generally ignored, and many nutrients that can easily reach toxic values are left out because they aren't deemed nutritionally essential.

Anyway, when it comes to home-made food I found that my own recipes and the most popular recipes online were generally AAFCO-compliant, with a couple notable exceptions.

1. Methionine. Almost all meat-based recipes exceed AAFCO's upper limit of methionine, which is 1.5% on a dry matter basis or 3.75g per 1000kcal. This limit is based on studies associating neurological problems with high concentrations of methionine. Naturally, meat (including organ meats) contains a lot of methionine. I found that rice or peas can easily be used to balance that out, which would explain why many canned foods include such ingredients even though they don't require binding agents like kibble does. Using high-calorie meats such as lamb also balances this out, at least when using per-calorie measurements, but is still problematic on a dry-matter basis. That said, meats tend to contain a much higher ratio of methionine to cysteine than grains or vegetables would, so I would assume that much more of the methionine would be converted into cysteine in cats on a meat-based diet than would be seen in a diet with veggie/grain fillers. I haven't been able to quantify this difference, though, so I'm not sure.
2. Minerals. This is not usually a problem with recipes using whole bone (including marrow), but makes things difficult when using eggshell calcium or calcium carbonate. I couldn't get complete numbers for MCHA, so I can't comment on that.
   
   • Iron is hit and miss. Usually meat can account for all of the iron requirements, but poultry meats seem to struggle a little. It tends to be very close, though, so in a diet that rotates multiple proteins I wouldn't be concerned. Poultry-only recipes are fine if they include whole bone.
   • Magnesium can easily be provided by eggshell powder, but not calcium carbonate.
   • Copper, zinc, and manganese are consistent problems. Bone gelatin and/or organ meats cannot provide these minerals without throwing other things way off balance, and eggshells do not contain any significant amount. Some veggies can provide these (it appears some commercial foods may use veggies towards this purpose), but the quantities required would bring up other concerns that are not addressed by AAFCO. It looks like synthetic supplements or whole bone are the only good ways to provide these minerals, yet I haven't seen such supplements recommended in any recipes using bone substitutes.
3. Vitamin D. Most recipes get plenty from egg yolks and/or fish oil, but I thought I should point it out for those dealing with food allergies. There is some vitamin D in muscle meat and whole bone, but not enough to meet the AAFCO requirements. It's hard to say how important this is, since cats can synthesize their own Vitamin D (albeit inefficiently), and AAFCO has repeatedly lowered their minimum requirements for it over the years. I didn't really look into alternative dietary sources of this vitamin, but it may be worthwhile. I personally wouldn't recommend a synthetic supplement, as it would be very easy to overdose. At the very least, we should make sure our cats have plenty of opportunity to bask in sunlight.

Any thoughts on these? The minerals in particular got me a little worried. I haven't had time to check the AAFCO citations to see what the basis is for these particular values, but I plan to. Has anyone had issues with long-term use of recipes using eggshell powder as a calcium source?

 

[EmmiTemmi]

I agree with pretty much everything you've written here. I did my own calculations on some homemade raw recipes and prey model raw recipes and came to the same conclusion. Although I couldn't find any sources of chicken bone composition to include those in my calculations. Do you have them? Because I always found that Fe, Zn, Cu, Se, and Mn were coming out low, no matter if red or white meats were used.

I haven't used raw long term, and have been hesitant to switch fully until I know all the nutritional needs of my cats are being met. I was also having trouble with some of the vitamins like Thiamin and Choline, which always seemed to be too low. And even supplementing with B vitamin complexes left Choline at a too low level.

I'll be interested to hear what anyone else on this site thinks.

 

[sophie1]

This is such a detailed and well-researched post that it deserves a response....

Feeding real whole bone in some form would address your concerns about minerals, no? If you plan to use eggshells exclusively, then probably best to go with Alnutrin as that mix supplements the missing minerals (check ingredient list), or EZcomplete. Or, use human grade bone meal instead of eggshell for your own homemade supplement mix.

Regarding vitamin D, that's an excellent point for indoor cats especially, and a good reminder why fish oil is mandatory for homemade foods. 1,000 mg/week/cat is a minimum amount, so doubling that should be safe. I buy the Iceland unscented and use the upper end of Dr. Pierson's recommended range, because one of my cats gets dandruff on his back if I use less. I also make food in small batches and freeze only a couple of days at most after adding the fish oil, so there should be minimal loss of nutrients. This is important for some supplement mixes as well - EZComplete doesn't require added fish oil but I believe Alnutrin does.

The methionine issue is interesting, especially if it's driving the addition of useless fillers to cat foods. I suspect this is a non-issue. Why would an obligate carnivore not be able to handle a 100% meat-based diet?

 

[EmmiTemmi]

Feeding real whole bone in some form would address your concerns about minerals, no?

But will it? I haven't been able to find many sources on the composition of chicken bone. And from the few scientific articles I could find (Which included Ca, P, Mg, Mn, and Cu), only the Mg met the AAFCO requirements. I'd really like a better source of bone composition though. Do you have one?

 

[prairiepanda]

Using a variety of meats takes care of the thiamine and choline. Chicken and pork, for example, contain a lot of thiamine, as do some other meats. Pale-coloured meats seem to be highest in choline. Egg yolks also provide a lot of choline, and can be used to supplement meats that are deficient. Vitamin B supplements actually have very little choline in them, and are more useful for meeting folic acid and biotin requirements. Thiamin levels vary substantially between different meats, with some such as pork having unusually high levels and others like chicken having extremely low levels. Organ meats usually have a lot of thiamin as well, so that helps. Those cooking their food shouls probably supplement with synthetic thiamine, as cooking will destroy most of it.

Diversity of proteins is important; every protein I looked at was deficient in some way as a single protein, but each one is deficient in different areas, so rotating proteins would give a good balance. If someone needs to feed a single protein for whatever reason, they will have to be extra careful.

As for the whole bone, I didn't bookmark my source for the mineral values on that because the source didn't really meet my standards. It gave me AAFCO compliance in my calculator in most recipes, but I'm still searching for a better source. Most studies only tested calcium, phosphorous, and magnesium so that isn't particularly helpful. The nutritional value of bones likely also depends on the type of bone and how much marrow is in it as well.

 

[mschauer]

The nutritional value of bones likely also depends on the type of bone and how much marrow is in it as well.

This is precisely why I don't use bone but rather use MCHA (freeze dried bone). I have a fairly complete nutrient profile from the manufacturer of the product I use.

I have spent many hours trying to find a source for the nutrient composition of whole bone. I found many sources but they were inadequate for one reason or another. In addition to the concerns you note, also beware of sources that show the nutrient content of "bone" but which actually uses the output of a de-boning machine. Such output will have a not insignificant amount of meat left clinging to it.

 

[mschauer]

1. Methionine. Almost all meat-based recipes exced AAFCO's upper limit of methionine, which is 1.5% on a dry matter basis or 3.75g per 1000kcal. This limit is based on studies associating neurological problems with high concentrations of methionine <snip>

You don't need to worry about exceeding the AAFCO upper limit on methionine. The upper limit is only a concern with supplemental methionine. Naturally occurring methionine, like what is found in meat, is metabolized differently. Sorry I don't recall more details.

As for vitamin D, are you looking at the most current AAFCO recommendations? I ask because the minimum was lowered recently from 750 IU/kg DM to 280 IU/kg DM.

 

[EmmiTemmi]

This is precisely why I don't use bone but rather use MCHA (freeze dried bone). I have a fairly complete nutrient profile from the manufacturer of the product I use.

Any chance you could share?

 

[mschauer]

Share what? The nutrient profile? It wouldn't be of use to you unless you also use MCHA. I can certainly provide it though. I've posted it before. Let me see if I can find it. If not I'll repost it.

 

[prairiepanda]

This is precisely why I don't use bone but rather use MCHA (freeze dried bone). I have a fairly complete nutrient profile from the manufacturer of the product I use.

I have spent many hours trying to find a source for the nutrient composition of whole bone. I found many sources but they were inadequate for one reason or another. In addition to the concerns you note, also beware of sources that show the nutrient content of "bone" but which actually uses the output of a de-boning machine. Such output will have a not insignificant amount of meat left clinging to it.

I wanted to include MCHA in my calculator, but couldn't find one with sufficient composition data. Would you be able to share yours? It's a shame that MCHA is so prohibitively expensive; it would be the most controllable mineral source....

 

[mschauer]

I wanted to include MCHA in my calculator, but couldn't find one with sufficient composition data. Would you be able to share yours? It's a shame that MCHA is so prohibitively expensive; it would be the most controllable mineral source....

It is expensive. I really don't recommend using the nutrient profile for it as the nutrient profile for whole bone. For one, you would need to know the moisture content of the whole bone in order to adjust the nutrient amounts.

 

[mschauer]

I found my old post. It isn't the entire profile. I also found the email that used to have the documents from the manufacturer as attachments and the attachments seem to have disappeared.

I do have the analysis though. When I get home tonight I'll see what I can get you. Worst case I can export it from my database.

 

[mschauer]

I found the original documents. They were safely tucked away in Evernote. I uploaded them to a Google directory that already has public access. You want the files that start with "MCH-Cal" :

Raw Recipes - Google Drive

 

[mschauer]

At the very least, we should make sure our cats have plenty of opportunity to bask in sunlight.

FYI: Cats don't synthesize vit D when sunlight strikes their skin the way some mammals do.

 

[EmmiTemmi]

I found the original documents. They were safely tucked away in Evernote. I uploaded them to a Google directory that already has public access. You want the files that start with "MCH-Cal"

Thank you! So helpful. I know it's in dry basis, but assuming 20-40% moisture in bone (avg to 30% for simplicity) then you can get the gist of mineral and nutrient content of bone.

 

[mschauer]

That's a bit loosey-goosey for me but to each his own.

I don't believe the values in the documents are on a dry matter basis. They are values for the product which will have some moisture. I don't see the moisture in the documents. I think I got the moisture verbally from the manufacturer. I'll check what value I have in my database.

Edit: The moisture value (4.2 %) is in a document I didn't upload at first. It's there now. (MCHA Std others 250. B030-1.doc)

 

[prairiepanda]

Thanks for the data! I wasn't planning on using it as whole bone data, I actually wanted to add MCHA as an ingredient in my calculator. I'm still hunting for a good source on raw whole bone data.

As for vitamin D, you are correct! Cats do possess pathways for synthesis of vitamin D, but their pathways are independent of UVB exposure. I need to pay more attention in class, it seems! That said, vitamin D synthesis in cats is extremely inefficient compared to photosynthetic methods, so they absolutely need dietary sources of Vitamin D. Those who can't use fish oil or eggs should be careful.

 

[sophie1]

This is precisely why I don't use bone but rather use MCHA (freeze dried bone). I have a fairly complete nutrient profile from the manufacturer of the product I use.

I may have missed something, but is there a reason why you'd expect freeze dried bone to be nutritionally superior to fresh bone?

I thought you were using freeze dried bone in order to get more precise control of bone quantity in recipes and to enable you to make cooked recipes with bone, not because of an expected difference in nutrient content. Since I feed raw with bone from 4 different species and find that my cats do well with a fairly wide range of bone content, I don't have a need for that level of precision.

 

[mschauer]

I may have missed something, but is there a reason why you'd expect freeze dried bone to be nutritionally superior to fresh bone?

??? I've never said I thought MCHA was nutritionally superior to fresh bone.

 

[prairiepanda]

It seems that even with using MCHA as a calcium source, zinc and copper are still deficient according to AAFCO. I'm hesitant to supplement zinc, but will look into the research more.