A "must read" book by Dr. Elizabeth Hodgkins: "Your Cat - Simple Secrets to a Longer, Stronger Life"
A Partial Nutrient Breakdown of the Home-Prepared Raw Diet
An extraordinarily kind and regular visitor to this site, Shelby Gomas, did something I've always wanted to do, but never got around to--he made a batch of the cat food based on the exact specifications on the "with bones" recipe on this site and then took it to a lab for analysis of some of the diet's macronutrients. He has very generously agreed to allow me to reproduce the results of that laboratory analysis here. There are critical components of a cat's diet that are not included in this analysis. In other words, here's what this analysis does and does not reveal:
- It tells us how one batch of this food stacks up against commercial food with regard to some key macronutrients.
- It does not reveal how this food compares to other commercial diets with regard to the all the micro and macronutrients that you will find listed on many pet food labels or in the extensive veterinary nutritional literature prepared by leading veterinary universities or pet food companies.
Bear in mind, too, that there is no guarantee that if you make the food according to the same specifications that the numbers would come out precisely the same, since there are necessarily going to be slight differences in each batch based on where you sourced your meat and organs and how long it was stored. That said, this is useful information to have if you're new to feeding raw and want to know more about some of the macronutrients in the diet, if you're concerned whether the all-important calcium-to-phosphorus ratio is correct (it is), and whether the diet meets the AAFCO minimum requirements for Taurine (it does).
I am supplying those data from that lab analysis here as a courtesy to site visitors, but remember that the credit for this effort all goes to Shelby. Again, please bear in mind that this analysis does not contain an analysis of other nutrients such as zinc, copper, iodine, magnesium, and others that you might find on a pet food label or in the scientific literature prepared by some of the pet food companies. But it is all I have in the way of data to evaluate some of the key components of the diet in a way that satisfies some of the more scientifically-minded visitors to this site.
In a perfect world, the companies that make cat food products to sell and the veterinarians who endorse them would pool their impressive talents and considerable resources--the kind that I simply do not have at my disposal--and conduct a thorough, unbiased, scientifically rigorous and complete analysis of this and other homemade raw diet recipes and include data on what precisely went into the diet, how long it was stored, how much key nutrients degraded over time and under what conditions, and so on. That way, we could know with more certainty if the diet truly meets every known nutritional requirement of our little domesticated carnivores. Wouldn't it be great to know, for example, how an analysis of a raw chicken diet compares side by side to a raw rabbit diet? And if the apparent Taurine depletion we know occurs in a raw rabbit diet, as demonstrated by the Winn Feline Foundation's study, occurs as well using other meat sources? There are so many things I wish I knew.
But it's not a perfect world, and those of us who have lost faith in many of the commercially available foods out there are left to our own devices and to do the best we can. I hope this is just a start, and that someone with the money and resources eventually provides a more thorough analysis. I and many others would welcome and applaud such an effort. As it is, many pet food companies and a good number of veterinarians appear to me to be so reflexively 'anti-raw' that there is no cacophony of noisy voices out there demanding such an evaluation. Maybe that will change one day.
A Note on Dry Matter Basis.
I have taken the liberty of including in the analysis a conversion to percentages on a dry matter (DM) basis, since this is the convention best used for comparing different brands of dry and canned food on an equal basis. You may notice, for example, that if you're looking at the "guaranteed analysis" label on a canned food and then on a bag of dry food, at first glance the dry food might appear to contain more protein than the canned. But look closely at the label and notice that the moisture content in the canned food is, of course, higher. So to really do a side-by-side comparison of the two foods, you'd need to subtract the moisture and then compare the two.
- DM is calculated by looking at the nutrient percentage divided by the reciprocal of the moisture percent. In other words, the reciprocal of the moisture content is simply the percent of the food that isn't water.
- The simple two-step process used to determine the DM basis of a macronutrient analysis of food goes like this: First, calculate the total dry matter in the food by subtracting the percentage moisture from 100 percent. If a food is 75 percent moisture, it is 25 percent dry matter. 100 minus 75 is 25. Second, divide the listed macronutrient percentage by the dry matter percentage. If looking at protein, for example, and it's listed at 10 percent, you divide 10 percent by 25 percent to calculate the DM basis for protein (40 percent in this hypothetical case).
- Finally, FYI, if you're looking to also calculate the carbohydrates in a given canned food, there is a way to do that using a third step. Pet food regulations (such as they are) do not have the word "carbohydrate" on the label. Ash is often listed on cat food labels, however, and this is useful for calculating the carbohydrates in a given food. (Ash is just what you'd think it is: it's what remains after the food is burned, consisting basically of elements like zinc, selenium, calcium, and phosphorus.) So, to calculate the carbohydrates in our hypothetical example of a food with 75 percent moisture, you use the first step above. Carbohydrates is equal to 100 percent minus the protein, fat, and ash.
A Note on AAFCO.
I would be remiss if I didn't offer my opinion here on AAFCO. Many people take great comfort in seeing a can or bag of food that claims that it means all the Association of American Feed Control Officials (AAFCO) minimum standards. I take no comfort in AAFCO.
It's important to understand what AAFCO is and what it isn't. A pet food can carry the AAFCO claim if it, or a member of its related family of products, has been tested on a small population of animals for six months and has been shown to provide adequate nutrition. Six mongths! Six months.
Please do not confuse this with the notion that it means the food is truly health-building and health-sustaining for life. If a can or bag is labeled as meeting AAFCO standards, all that means is that animals don't DIE when fed only that food for six months and don't lose more than 15 percent of body weight. So as long as the animal is alive, hasn't lost 15 percent of their body weight, and a minimal blood test reveals that a handful of values are in an acceptable range, the food gets the AAFCO seal. Moreover, only eight animals need to participate in the feeding trial, and only six need to complete the 26-week trial.
The diet being tested fails if any animal shows clinical or pathological signs of nutritional deficiency or excess. Specific minimum values for the blood tests are given, and applied to the average result of all participating animals that finished the trial.
Remember, the rules for AAFCO are that if one particular product in a manufacturer's line was tested and found to meet the AAFCO standard, the company can include this same statement on other products in the same family. So when you see an AAFCO statement on a pet food label, you have no way of knowing if that specific product was actually tested in a food trial. Moreover, the AAFCO protocols include blood tests that screen only four different blood values at the beginning and end of the food trial: RBC, hemoglobin, packed cell volume, and serum albumin. Even the basic veterinary blood profile screens for at least 25 values.
Personally, I no longer take a great deal of solace in seeing a label on a can or bag that says it meets the AAFCO minimums. Is it better than nothing? Of course it is. But does it give me full faith that the nutrients supplied in that particular can or bag contain everything a cat needs to be healthy? Not even remotely close. Many nutritional deficiencies or excesses will not be apparent within a 6-month period, as they often take much longer to develop. That's why I prefer the method of attempting to reverse-engineer what mother nature intended for animals. Is it guaranteed to have every last nutrient your cat could possibly ever need? No. It isn't. But it's the best I can offer.
You'll have to make up your own mind on where you want to put your faith when it comes to deciding what to feed your carnivores. It's not easy, I know. Believe me, when I first started serving to this diet I was extremely nervous. Not fully appreciating back then the shortcomings and loopholes associated with pet food labeling and AAFCO standards, I was uneasy serving food that came out of a container that didn't have that ostensibly reassuring "100 percent nutritionally complete" logo on it. Now? After seven years of feeding this way? I feel pretty darn confident when I grind up a whole free-range chicken or rabbit in my spotlessly clean grinder and then carefully measure out the other ingredients, that I've done the best I can for the cats I'm responsible for. And that by exercising responsible control over what goes into them and nutritionally fuels their lives, I'm not knowingly exposing them to the multiple illnesses out there that are related to feeding them one of the scores of species-inappropriate diets that I would be buying in a store or from a veterinary clinic.
So . . . with all those caveats, here we go:
Minimal analysis of raw diet made according to specifications for the "with bones" recipe (using whole chicken):
Moisture 75.25%
Protein 55% DMB
Fat 28% DMB
Fiber 5.6% DMB
Ash 11% DMB
Calcium 1.9% DMB
Phosphorus 1.7% DMB
Taurine .20% DMB
So? Am I generally pleased with how these numbers came out? Darn tootin' I am.
Just for starters, the calcium-to-phosphorus ratio came out in a range I'm very happy with (1.14:1.0), the moisture content is a delightful 75 percent, and the Taurine is double the AAFCO minimum. [1] Is there more I'd like to know? Yes, of course there is. Lots, lots more. But thanks to Shelby, we now have at least some sense of where the homemade, grainless, vegetable free raw diet roughly stands in comparison to commercially prepared cat food diets and AAFCO minimums and some idea of where it stacks up against some of the macronutrients in the diet that a cat was biologically built to eat: a field mouse.
- If you're interested, an adult mouse is roughly 67 percent water, has a calcium-to-phosphorus ratio of 1.1:1, has 3 percent carbohydrates, consists of about 57 percent crude protein, and contains 23 percent fat. [2] A very popular and widely used commercial dry diet, just as a comparison, has hardly any water, 36 percent carbohydrates, 33 percent crude protein (much of which is derived from plant, not animal, matter and is therefore not nearly as bioavailable), and 23 percent fat.
1. AAFCO Nutrient Profiles for Cat Foods.
2. Profiles of nutrient composition of whole vertebrate prey, excluding fish (fed in
zoos), May 29 2002, conducted by Ellen S. Dierenfeld, PhD (Animal Health Center, Wildlife Conservation
Society, Bronx NY), Heather L. Alcorn (Dept. of Animal Science, Cornell University, Ithaca NY), and
Krista L. Jacobsen, MS (Animal Health Center, Wildlife Conservation Society, Bronx NY).