Judging the Biological Value of a Dog Food Protein

by Mike Sagman
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Judging a Dog Food's Protein Quality
Feathers. Beaks. Hooves. What do these three animal body parts all have in common?

Give up? All three contain an unusually high percentage of protein.

But unfortunately, it’s basically worthless protein, protein that’s nearly impossible for any dog to digest.

High Content May Not Mean High Quality

Just because a particular dog food boasts a high protein content doesn’t necessarily mean the protein is beneficial.

You see… a product’s stated protein percentage ignores a very important factor… its quality… its nutritional value to the dog.

In other words… a protein’s “usability”.

Biological value… or “BV” as it is known… is a scientific way to compare the usability… and digestibility… of different protein ingredients.

BV uses a number value to indicate how easily a protein is taken up by a dog’s tissues.  So, the higher a protein’s biological value… the better its usability.

For those readers who tend to be mathematically inclined… the formula for biological value looks like this…

BV = (protein used/protein available) x 100

The Incredible (Edible) Egg

Due to their nearly perfect usability, chicken eggs are used as the official benchmark by which all other proteins are judged.  So, eggs are assigned a reference biological value of 100.

Take a look at the following table1.  Notice the substantial difference in protein usability of these typical ingredients…

biological-valueFrom this table, it’s easy to conclude…

Animal protein can be expected to demonstrate a significantly higher biological value than vegetable protein

In other words… animal proteins are simply more nutritionally usable.

That’s why it’s so important to make it a habit to check every dog food label’s list of ingredients.  And rate the product’s main source of protein.  Otherwise… you may be depriving your dog of quality nutrition.

Be sure to read my article… Why You Must Never Trust Stated Protein Percentages to Compare Dog Foods.

  1. Palika, Liz, The Consumers Guide to Dog Food, New York, Howell Book House, 1996 ↩
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  • http://DogFoodAdvisor.com/ Mike Sagman

    Hi Shawna and Victoria,

    Aside from a previous chart in a previous article posted by Dr. T. J. Dunn (and one I can no longer find on the Net), it’s important to remember that the biological value of any ingredient is species dependent.

    And almost all the BV figures available appear to be based upon human physiology.

    If any of you come across with a reliable paper or study which includes accurate BV stats for dogs (or cats), please post a link here.

    Thanks.

  • Shawna

    Victoria ~~ the biological value (per the below linked website) is 60.  Corn gluten meal would be the same as it is the same amino acids from protein just in a concentrated amount.

    http://www.food-info.net/uk/protein/bv.htm

    I see Mike’s chart is slightly different from the linked one.. Either way, the BV would be the same as whole corn.

  • victoria

    Mike, do you know what the biological value of corn gluten meal is? I cant seem to find it anywhere. 

  • http://DogFoodAdvisor.com Mike Sagman

    Hi Mike P,

    Currently, he’s eating a kibble containing 38% protein (dry matter) and topped with a wet food at about 40%.

    But we do switch the dinners around.

  • Mike P

    Mike S what is the protein % you feed your Bailey?Just curious…

  • SHARON VRLA

    …for got to mention, their weights are good and stool is good, but poodle seems to have a hard time ‘getting it out’. (good consistency, just struggles) I want my girls to be healthy and comfortable, and I worry that sometimes they ride the fence.

  • http://DogFoodAdvisor.com Mike Sagman

    Hi Sharon… Sounds like you’ve got quite a variety there. In most cases, breed-specific dog foods are of questionable value and are probably unnecessary. Unfortunately, due to the biological uniqueness of each pet, I cannot provide customized diet recommendations for each reader.

    For more help, please check out my reviews and visit our FAQ page. Look for the topic, “Help Me Choose a Dog Food”. Or check back for a possible response from one of our other readers.

  • SHARON VRLA

    Hi, I have been feeding my dogs THK Keen with various meats like boiled chicken, or cooked ground buffalo or boiled fresh caught salmon. The thing is, they do pretty good with their diets, but they are very different dogs. One is a three year old Malti-poo and the other is a ten year old toy poodle. The ten year old is thriving, but I think she needs more of something, I just can’t figure out what. They get fed abt a 1/4 cup each in the morning and the same at night, with a few small meat treats in btwn, but the poodle wakes up some mornings with a ferociously growling stomach and just wants to eat grass, like she’s in some sort of daze. The Malti-poo will eat, but I think she’s bored with her diet. There are always SG Bark at the Moon crunchies out, which the Malti will eat regularly, but the poodle will only eat them in a what seems a light bout of starvation, and I dont think she really chews them! Any ideas on what might do better given the breeds and ages and reactions?

  • Scarlett’s Mom

    If you are looking for an egg based dog food Royal Canine (vet prescription) makes one. My Westie has bleeding ulcers so she cannot eat any meats. This meal is the mildest form of protein for allergic dogs and she has been doing well on it.

    Since she loves fish, I cook a scrambled egg in the microwave (no oils) and mix a tablespoon or so of baked catfish in it for flavor. Fresh water catfish has virtually no oil in it so its very mild.

    Hope this helps.

  • Barbara Eckert

    I cook our dogs’ daily lunch diet (veggies, brown rice, chicken, one or two crushed garlic cloves) plus they have dry By Nature Organic Chicken supplemented. Eggs are added to the cooked diet 2X/week. Our Cocker experienced irritating hot spots 2 consecutive summers and the vet gave me a prescription which didn’t seem to help. I did some reading on the web and found out carrots and sweet potatoes could be the culprit so I omitted those from their diet. Scooter has not had the hot spots since then, however, he has been itching badly and continuously licks his right paw. I’m thinking the culprit might be spring weeds or something popping up in the lawn, any suggestions? This just started about a month ago when the weeds appeared.

  • http://DogFoodAdvisor.com Mike Sagman

    Hi Gina… I’m not aware of such a problem with eggs and vitamins. I take my own human vitamins with my eggs every morning.

  • Gina

    I have been feeding my Great Pyrenese puppy 4-5 duck eggs a day mixed in with her Exclusive Lg. Breed puppy food. She is growing great her fur is so soft shiny and beautiful, but then I read the post about the eggs being bad for absorbtion of some vitimins. Should this be cause for me to worry if she seems to be doing fine. I have been feeding her this everyday since we got her at 8 weeks old and she is now 4 1/2 months old….Help I only want what is best for my gal..G

  • http://DogFoodAdvisor.com Mike Sagman

    Hi Buddy’s Mom… The fact Buddy is doing so well on your vet’s prescription food, I’d be reluctant to make the switch to a meat-rich diet without considerable forethought or professional help. I’m sure there are a number of hypoallergenic or limited ingredient products that might help.

    Unfortunately, since I’m not a veterinarian, I cannot provide specific health advice or product recommendations. Please see our FAQ page and our reviews for more information. Or check back for a possible response from one of our other readers. Wish I could be more help.

  • Buddys Mom

    Hi Mike:
    My cock a poo had suffered from many hot spots and was dragging his rear end often. Since my primary physican’s only solution was cortisone shots, I consulted a doggie dermatologist at the Univ of Penn veterinary clinic. He advised since there is no blood test for food allergies, an elimination diet would at least be a starting point. Although it was difficult to determine an exact allergy, the dermatologist’s recommendation was Purina HA (soy) food. Buddy has been on this diet for several years and we have been able to determine that beef may be his true allergen. Therefore, I supplement his diet with bits of chicken, an egg here and there and at times some salmon. It has recently come to my attention that this food is not very well rated. Since Buddy is now eight years old, I would like to transition to an option that he can tolerate with more nutritional value. Any suggestions how to go about this?

  • http://DogFoodAdvisor.com Mike Sagman

    Hi Theresa… Since each dog responds to a particular food in its own unique way, it would be impossible for me to assure you feeding any specific product would help control your dogs’ allergies. Unfortunately, I cannot provide customized product recommendations for each reader. For more information, please check out my reviews and visit our FAQ page. Look for the topic, “Help Me Choose a Dog Food”. Or check back for a possible response from one of our other readers. Wish I could be more help.

  • Theresa

    Hi Mike
    I have adopted two beautiful Saint Bernards and I have been feeding them for the last two years Acana Dog Food. They were first on Orjien but protien levels to high. I have them on Grasslands. They do well but tend to lick them selves. I’m not sure if it’s because we live in Las Vegas or if it’s coming from the food. I went to the vet and they say there is no such thing as giving a dog a blood test for food allegries. Is there something you can recommend, that helps my babies with this problem. They have some many probotics and digestive enzy. out there don’t know what to trust. Also I’m looking for a good dog treat (grain free) not made in china.
    Please help. I’m at my witts end…..Sincerely, Theresa

  • http://DogFoodAdvisor.com Mike Sagman

    Hi Roger… Unfortunately, there’s very little information available for pets. That’s because biological value can be a controversial representation of a protein’s true value. A more up-to-date (yet still controversial) method is known as the Protein Digestibility Corrected Amino Acid Score (PDCAAS).

    PDCAAS is a technique for judging the protein quality of a food and is based upon both the amino acid requirements of an animal and its ability to digest it. But unfortunately, only in humans.

  • Roger Prows

    Do you have a full table of biological values anywhere?

  • Molly D.

    Just a comment to follow up on Boxer’s previous post from Jan 3rd… dogs shouldn’t eat alot of raw egg whites as they contain a glycoprotein called Avidin, which binds to biotin (a B vitamin) preventing it’s absoption. They also contain inhibitors of the digestive enzyme Trypsin, which helps to break down and digest proteins.

    The yolk is the nutrient rich and beneficial part off the egg, and can be eaten raw.

    I often feed my dogs fresh chicken and duck eggs but I soft boil them (Trypsin inhibitors are destroyed by heat and light cooking cuts Avidin by about one third). I don’t even worry if I can’t fully peel the soft boiled eggs, the dogs will eat bits of the shells too.

  • http://DogFoodAdvisor.com Mike Sagman

    Hi Rafael… Since gluten contains the protein portion of a corn kernel, it is certainly possible for a dog to be allergic to this ingredient.

  • refael franco

    HI Mike
    i talk with my friend about corn free
    i want to know if i see “corn gluten meal” and talk with the service customer they told me thats the food is corn free and the corn gluten is just for protein and this is safe use for allergic dogs (to corn) . what you think ?
    regards franco

  • http://www.boxerurkabustaiz.es/oda.html boxer

    Why not just feed real eggs? They are cheap and easy to feed (raw or boiled).

  • Jonathan

    Ah good point. One other thing… Is there any dog foods that begin with fresh chicken, have no chicken meal or plant based protein boosters, but contain a respectable amount of meat protein? It seems like it should be possible, they would just have to use a substantial amount of fresh chicken meat. That’s a problem I have with fresh chicken… we know that fresh chicken loses water weight when cooked, but how do we know that the manufacturer simply isn’t just using a huge amount of it so that even after cooking, it’s still the true main ingredient?

  • http://DogFoodAdvisor.com Mike Sagman

    Hi Jonathan… That does sound like a good idea but unfortunately I’m not aware of any recipe like this. I’d imagine kibbling or canning an egg-based product might prove a bit of a challenge.

  • Jonathan

    Is there any dog foods that use only eggs as their protein source? It would seem that would be even better than chicken meal considering the BV of eggs.

  • dean

    it is so stressful to read the lable on dog food’s. i believe our dog’s are what they eat.i look at my dog’s then look at other people dog’s and i know mine are very healthy just by the skin and coat and those clear bright eye’s and how happy they are. i have a yorkie and he is very calm but very active and my toy mini schanuzer is a picture of health… we have recently adopted 3 new 4 legged kids due to two families out of work and moving out of state it has only been about one week and the new 4 legged kids are looking much better and it’s all about the food. i make home made food and use home made with halo’s dry formula on the new kids… they came with no food to make it easy on the new food given but they all had no tummy issue’s at this food. and i can say i feel like i am giving them a new start to health and a longer life as well as being happy or they would have been turned into the animal shelter i fell man or animal we are what we eat and the dog company that uses by-products need to stop and if they make dog food should make food not left over hulls of whta food was and use what a dog or cat live on not get by on until they get sick from no food as a whole but fill up the bag with too many vitamin’s/ minerals in some a over load. that is why i made my pets food and that is why i am using halo for the new kid’s along with my home made food i don’t know if they will be put compeletly on home made yet or not i did not want to change what they ate the new kids but i trust halo in fact i do not know what the two families feed these new adopted dog’s but their coats were just awful and in only a few day’s it is starting to shine so that is what food is about. working from the inside out. i wish the dog food companies would go out of business that use left over junk i will never buy junk by-products, ever. food is just that food and not only that but what a dog needs not just to fill it up.just do your research and research more and more even at what goes on the table for humans as well.something needs to change in the food business period.heathy is what everyone is wanting.thank you very much