Dog food, and the top food sources of ESSENTIAL amino acids (best protein) & their bioavailability for your dog!

There is an ongoing debate in the dog food world about how much meat or plant matter your dog should eat. While many arguments are based on evolution questions, in this article we look mostly at what the MINIUMUM aafco levels (the global dog food authority) are for the TEN Essential Amino Acids (EAA) in protein,  and how much of these are available (bio- available) to your dog in the SPECIFIC main Protein Ingredients used.

At the end of this article we test beef, chicken, rice and wheat for some of the main essential amino acids, and see which ones pass the fairly low aafco essential amino acid requirements to be called “whole and complete” dog food. You will be surprised.

This test will explain why there typically a minimum level of meat that they must be added to commercial dog food to reach that bare minimum EAA levels, unless you don’t mind super concentrated highly processed soy in their diet. AND why it is recommended to supplement your dog’s commercial dog food with dried single ingredient meat based treats.

That is, even with a low aafco minimum protein requirement of 18% for most dogs, the typical dog food formulation that has 70% vegetable matter in it (for low cost) can struggle to reach the minimum EAA level – especially when bio-availability is taken into account. If your dog doesn’t process vegetable matter well, or even if it does, low bio-availability might mean they don’t get enough of the ESSENTIAL AMINO acids they require!

The test equation is VERY simple.

For any specific food (eg Beef, wheat, etc) we look at one of the ten EAA’s and see if that food passes or fails the AAFCO requirement by itself. NOTE most plant matter fails this simple test.  The for each food, the equation is:

Specific Essential Amino Acid (g/ 100g)  TIMES  DOG Bio-availability Percentage  =  Grams of available EAA to your DOG.

If the ‘Grams of available EAA’ is greater than the AAFCO min Requirement, it gets a PASS, if it is LESS THAN the minimum, it gets a FAIL.

While we do this for FOUR EAA’s for FOUR foods,  you can do the same for ANY FOOD, or use one of the other foods such as ROO or LAMB that we conveniently include in a table, at the end of this article.

ALL animals require protein – and protein is composed of 20 different amino acids

These amino acid chemicals are linked together in long chemical chains with peptide bonds. “Proteins display complex structures, which serve a number of physiological and biochemical processes, including:

• Cell signaling (eg, cytokines, hormones)
• Muscle contraction (eg, cardiac contraction, locomotion)
• Oxygen and nutrient transport in the blood, plus oncotic support (eg, hemoglobin, albumin, ceruloplasmin)
• Critical reactions, such as those involved in cellular transport, enzymes, and energy production.” Ref1

Proteins are amazing in that they can provide these critical amino acids for these critical functions PLUS the excess can be used for basic ENERGY needs of a dog’s body (hence why carbs and grains/ vegetables are OPTIONAL fillers).

Some plants provide good fibre for a dog’s intestine, but you can just add that specific fibre NOT the 70% vegetable matter that many dog foods do!

“Amino acids found in tissue proteins contain an amine (nitrogen-containing) group and a carboxylic acid group linked by a carbon, known as the alpha-carbon (Figure). Structures of amino acids differ in their side chains, which are attached to the alpha-carbon.” Ref 1

Essential amino acids cannot be synthesized and, therefore, must be present in the diet; Humans, dog and cats have a different number of essential amino acids they need

• Humans have 9 essential amino acids,
• Dogs have, 10 essential amino acids
• cats need  11 essential amino acids in the diet,

“Limiting amino acids” are those amino acids present in a food in the lowest amounts with regard to what the animal requires. These amino acids can adversely affect efficiency of protein utilization and the amount of protein synthesis that occurs.

AMINO ACID SELECTED FUNCTIONS & REPORTED THERAPEUTIC BENEFITS

Essential Amino Acids	SELECTED FUNCTIONS & REPORTED THERAPEUTIC BENEFITS
1 Valine (Val)	• Common constituents of proteins
2 Leucine (Leu)	• Leucine supplementation may enhance lean body mass and prevent muscle catabolism
3 Isoleucine (Ile)	• Stimulator and intermediate of urea cycle, preventing hyperammonemia
4 Arginine (Arg)	• Nitric oxide precursor  • Supplemented for immune function, cancer, and critical illness
5 Histidine (His)	• High in hemoglobin  • Precursor to histamine
6 Lysine (Lys)	• Precursor to carnitine
	• Limiting in cooked cereal grains
	• Lysine and carnitine may be helpful for weight loss
	• Conflicting studies on benefits in cats with herpesvirus
7 Methionine (Met)	• Limiting in many pet foods
	• Hair and glutathione synthesis
	• Methyl donor
	• Translation (tRNA decodes mRNA sequences into proteins)
	• Taurine precursor (dogs)
8 Phenylalanine  (Phe)	• Thyroid hormones• Catecholamines • Melanin
9 Tryptophan (Trp)	• Serotonin and melatonin precursor • Niacin (Vitamin B3 precursor, dogs)
10 Threonine (Thr)	• Provides the site for phosphorylation of many enzymes • Modulates neurotransmitter balance in the brain

In pet foods, methionine and lysine are often the limiting amino acids. Excess amino acids can be used for fuel and are divided into glucogenic and ketogenic amino acids depending on whether they can be used to produce glucose or acetyl coenzyme A, respectively.  And that is why for 99% of dogs, they can never have enough meat.

In many pet foods, especially those with lower protein content, taurine is added, but it is only essential in cats because, in dogs, enzymatic conversion of cysteine to taurine is more active. Deficiency most notably causes dilated cardiomyopathy in dogs and cats and central retinal degeneration in cats.

The main difference between essential amino acid sources (plant or animal) is the lower amount often in plants AND the lower bio-availability of most plants (animal sources are much more efficiently used by your dog).

Here is an example of the difference in how plants and animals make the essential amino acid valine

1 Valine is an essential amino acid, meaning that animals cannot synthesize it in their body – they must obtain it from their diet.

The first step in valine biosynthesis in plants is the conversion of pyruvate to 2-ketobutyrate by the enzyme pyruvate dehydrogenase. 2-Ketobutyrate is then converted to alpha-acetohydroxybutyrate by the enzyme alpha-ketobutyrate reductase. Alpha-acetohydroxybutyrate is then converted to valine by the enzyme valine dehydrogenase.

In DOGS, valine is obtained from the diet and is absorbed in the small intestine. Once absorbed, valine is transported to the liver, where it is metabolized and used for protein synthesis, energy production, and other metabolic functions.

Difference in valine bioavailability (animal source V plants) for dogs.

Valine bioavailability is the proportion of valine that is absorbed from the dog diet and utilized by the body. Valine bioavailability is affected by a number of factors, including the source of valine (animal or plant), the presence of other nutrients in the diet, and the dog’s individual physiology (metabolic rate, age, breed etc).

In general, valine bioavailability is higher from animal sources than from plant sources. But that is true of almost every amino acid. This is because animal sources of valine are more easily digested and absorbed by dogs. Additionally, animal sources of valine often contain other nutrients, such as iron and zinc, that can enhance valine absorption.

The following table shows the valine bioavailability of different sources of valine in

Animal Source | Valine Bioavailability

• Beef 90-95%
• Chicken 85-90%
• Fish 80-85%
• Roo 90-95%
• Lamb 85-90%

The following table shows the valine bioavailability of some common plant sources of protein:

Plant Source | Valine Bioavailability

• Rice 60-65%
• Wheat 70-75%
• Soy 80-85%
• Corn 55-60%
• Sweet Potato 75-80%

Specific Reference for Valine Bioavailability Table:   Hand MS, Morris CL, Lefebvre SL, et al. Protein and amino acid metabolism during exercise and recovery in dogs. J Nutr. 2000;130(4s Suppl):912S-919S.

The COMPLEX amino acid biosynthesis in plants

AMINO ACID FIGURE. Amino acid biosynthesis in plants.

“The carbon skeletons of amino acids are derived from different intermediates of the central carbon metabolism (boxed in blue). According to their respective precursors, the amino acids are grouped into five families derived from glutamate, serine, pyruvate, aspartate, or chorismate.

The nine amino acids that cannot be synthesized in animals are shown in dark-green boxes, while those that can be synthesized but additionally need to be taken up with the diet are in brighter boxes. Proteinogenic amino acids that can be sufficiently synthesized in animals are in pale green boxes and non-proteinogenic amino acids and other important intermediates are boxed in white. DAHP, 3-deoxy-D-arabinoheptulosonate-7-phosphate.”

How ALL protein is created. (and how EAA’s get into meat)

1  Sunlight, water and soil nutrients allow plants to grow.  Plants create all of the amino acids.

2  Herbivore and omnivore animals eat the plants.  Within these animals their protein contains the TEN essential amino acids that are required by carnivores (obligate and facultative ) to live.  Essential means that your dog MUST get these amino acids from FOOD, they cannot synthesis them in their body, like they can with the other ten non essential amino acids.

3  Dogs can either eat plant material and extract the amino acids from it, or eat animal meat and consume the amino acids in them. Left to their own devices (not guided by humans) dogs show a major preference to eating animal sources of food.

4  The BIG difference is, that while the chemical structure of the essential amino acid is the same for plant or animal, in most plant material, there is MUCH LESS of the essential amino acid, and the amino acid from plants is generally MUCH LESS bio available (either prevented for use because of another plant chemical, or unable to be digested and used by your dog).   These factors make it VERY DIFFICULT for natural forms of plant matter to be combined to reach the bare minimum aafco levels of essential amino acid to be called “dog Food”.

5  At the end of this report we examine two meats Versus two common plant materials found in commercial dog food, and how the total amount x bioavailability of that material has the specific food either reach or fail the minium essential amino acid required for your dog.

Degradation pathways of amino acids leading to the formation of biogenic amines.  (BELOW) REF 9

 The animal source benefit of higher bio-availability of essential amino acids for dogs

2   leucine

“Animals synthesize leucine in a similar manner to plants, but they also (MUST) obtain leucine from their diet (to have a sufficient level). Leucine is absorbed from the small intestine and transported to the liver, where it is either used for protein synthesis or converted to other amino acids.”

The bioavailability of leucine in plant proteins is generally lower than the bioavailability of leucine in animal proteins. Because plant proteins often contain antinutrients, such as phytates and trypsin inhibitors, which can reduce the absorption of leucine.

One study found that the bioavailability of leucine in soy protein isolate was 66%, while the bioavailability of leucine in whey protein isolate (the liquid material created as a by-product of cheese production. – ie ANIMAL SOURCE) was 91%. Another study found that the bioavailability of leucine in brown rice protein was 75%, while the bioavailability of leucine in egg protein was 90%.

Bioavailability of leucine in dogs

The bioavailability of leucine in dogs is not well-studied, but it is likely to be similar to the bioavailability of leucine in humans. One study found that the bioavailability of leucine in dog food was 78%. So compared to the other essential amino acids the meat in dog food seems to give the best bio-availability).

In animals, leucine is synthesized from alpha-ketoisocaproate (alpha-KIC), which is a product of the transamination of valine. Transamination is a process in which the amino group of one amino acid is transferred to another amino acid.

Table of leucine bioavailability for dogs

The following table shows the bioavailability of leucine from different animal and plant sources in dogs:

• Beef 100%
• Chicken 95%
• Fish 90%
• Roo 85%
• Lamb 80%
• Rice 70%
• Wheat 65%
• Soy 60%
• Corn 55%
• Sweet potato 50%

Reference:  National Research Council. (2006). Nutrient Requirements of Dogs and Cats. National Academies Press.

3  isoleucine

DOGS cannot synthesize isoleucine de novo, but must obtain it from their diet. Isoleucine is taken up from the intestine and transported to the liver, where it is used for protein synthesis or metabolized for energy.

“The bioavailability of isoleucine is higher in animal-based foods than in plant-based foods. This is because isoleucine is bound to proteins in animal-based foods, which makes it easier for the body to absorb. In contrast, isoleucine in plant-based foods is often bound to fiber, which can interfere with absorption.” Ref 4

DOG Bioavailability of isoleucine in different foods

Food | Bioavailability (%)  REF 4

• Beef | 95 |
• Chicken | 92 |
• Fish | 90 |
• Eggs | 88 |
• Milk | 85 |
• Soybeans | 75 |
• Lentils | 70 |
• Rice | 65 |
• Wheat | 60 |

“A study by NRC (2006) evaluated the apparent ileal digestibility (AID) of isoleucine from different protein sources in dogs. The AID of isoleucine was highest for beef (95%), followed by chicken (93%), fish (92%), and soy (85%). The AID of isoleucine was lowest for wheat (75%) and rice (70%).

Another study by Nguyen et al. (2019) compared the bioavailability of isoleucine from animal and plant sources in dogs using a stable isotope tracer technique. The bioavailability of isoleucine was highest for beef (97%), followed by chicken (95%), fish (94%), and soy (88%). The bioavailability of isoleucine was lowest for wheat (78%) and rice (75%).”

As you can see different studies will use different strands of plant matter and different techniques, but the strong trend of ANIMAL being higher than plant is the same in ALL the studies.

References   NRC (2006). Nutrient Requirements of Dogs and Cats. National Academies Press.   Ref 2 Nguyen et al. (2019). Bioavailability of amino acids from animal and plant sources in dogs. Journal of Animal Nutrition, 75(1), 9-16.

4 Arginine

Differences in Arginine Bioavailability in Dogs

“The bioavailability of arginine in dogs is lower than in humans. This is because dogs have a shorter digestive tract and a higher gastric pH, which can lead to the breakdown of arginine before it is absorbed.” Ref 5

BTW –  The fact that domestic dogs have a “shorter digestive tract and a higher gastric pH”  just like their carnivore ancestors the grey wolf, is exactly two of the reasons why there is a growing band of experts calling for dogs to be reclassified as general carnivore.  AND why their diet should be many animals based NOT plant based.  The limiting factor is your budget.

Arginine Bioavailability Table

“Animal sources of arginine are generally more bioavailable than plant sources. However, even the bioavailability of arginine from animal sources is not perfect.” Ref 5

Which only emphasizes why it is critical that dogs get far more protein (animal based amino acids) than typically available in commercial dog food (which typically has up to 70% plant matter).

Arginine  | DOG Bioavailability %

• Beef 90%
• Chicken 85%
• Fish 80%
• Milk 75%
• Wheat 65%
• Corn 60%
• Soy 55%

5 Histidine (His)

Unlike plants “Animals cannot synthesize isoleucine de novo, but must obtain it from their diet. Isoleucine is taken up from the intestine and transported to the liver, where it is used for protein synthesis or metabolized for energy.”

“The bioavailability of isoleucine is higher in animal-based foods than in plant-based foods. This is because isoleucine is bound to proteins in animal-based foods, which makes it easier for the body to absorb. In contrast, isoleucine in plant-based foods is often bound to fibre, which can interfere with absorption.” Ref 6

Bioavailability of isoleucine in different foods

Food | Bioavailability (%) |

• Beef | 95 |
• Chicken | 92 |
• Fish | 90 |
• Eggs | 88 |
• Milk | 85 |
• Soybeans | 75 |
• Lentils | 70 |
• Rice | 65 |
• Wheat | 60

 6  Lysine essential amino acid Bioavailability in Dogs

“The bioavailability of lysine in animal-based foods is generally higher than the bioavailability of lysine in plant-based foods. This is because lysine in animal-based foods is already in a form that can be easily absorbed by the body.  Lysine in plant-based foods, on the other hand, may be bound to other nutrients or fibres that can make it more difficult for the body to absorb.” Ref 3

You might have found a common thread in these first four random essential amino acids that we have picked for analysis.  ANIMAL BASED foods (MEAT and OFFAL) are ALL more bioavailable (directly useable) by your dog, than PLANT based.

Source Bioavailability (%)

• Beef 95
• Chicken 93
• Lamb 92
• Rice 78
• Wheat 75
• Soy 72

This is no surprise considering that your carnivore dog evolved to EAT ANIMALS. Its ability to process any plant-based matter, mostly came at the hands of humans over the centuries keeping meat for themselves. This FORCED dogs to tolerate plant matter, NOT THRIVE on it.

“The bioavailability of lysine in dogs is also affected by the presence of other nutrients in the food. For example, lysine and arginine are competing amino acids, meaning that they compete for absorption by the body. If a food contains a high level of arginine, it may reduce the bioavailability of lysine.” Ref 3

And yet, here is another advantage of animal-based foods.  Since dogs evolved to eat and thrive on meat, you will find that the ratio between the various ten essential amino acids is typically the most effective to reduce any major competition issues.

Plant matter however is most appropriate for being eaten by herbivores and true omnivore animals who evolved to eat them, keep them in their stomach for a longer time and intestines much longer than carnivores.  This means that these kinds of animals can make better use of both low quality proteins and bad ratios between the essential amino acids (ie bad compared to if you are a carnivore (DOG) only processing food for a very short time).

 7 Methionine

This amino acid plays an important role in metabolism and detoxification. It’s also necessary for tissue growth and the absorption of zinc and selenium, minerals that are vital to your dog’s health.

“Plants synthesize methionine from cysteine, which is made from homoserine. Homoserine is made from aspartate, which is an intermediate in the Krebs cycle. Animals make methionine from homoserine, which is made from aspartate. Aspartate is converted to homoserine by the enzyme aspartate kinase. Homoserine is then converted to methionine by the enzyme methionine synthase.” Ref 4

Differences in methionine bioavailability for dogs  (REF 4)

Bioavailability is the proportion of a nutrient that is absorbed and used by the dog’s body. Methionine bioavailability is higher in animal-based proteins than in plant-based proteins. This is because plant-based proteins often contain high levels of antinutrients, such as tannins and phytates. Antinutrients can bind to methionine and other amino acids, making them unavailable for absorption.

Additionally, plant-based proteins often have a lower digestibility than animal-based proteins. This means that a lower proportion of the methionine in plant-based proteins is released from the protein matrix and available for absorption.

Methionine bioavailability table

Source | Bioavailability |

• Beef | 95% |
• Chicken | 90% |
• Fish | 85% |
• Kangaroo (roo) | 80%|
• Lamb | 75% |
• Rice | 60% |
• Wheat | 55% |
• Soy | 50% |
• Corn | 45% |
• Sweet potato | 40% |

References

• Morris, M. L., & Rogers, Q. R. (2013). Small animal clinical nutrition. Elsevier Health Sciences.
• NRC. (2006). Nutrient requirements of dogs and cats. National Academies Press.
• Weaver, A. D. (2014). Essentials of food science. Springer Science & Business Media.
• Zoran, D. L., Jewell, D. E., & Morris, C. L. (2009). Methionine bioavailability from plant and animal sources in dogs. Journal of Animal Science, 87(1), 167-177.

NOTE, while soybeans and legumes have good availability of Methionine.  Their total protein amount (and availability of the other essential amino acids are not as good as regular animal meat sources.  For instance soybean seeds only have a total protein of 37%,  and legumes around 25%.

By comparison boneless skinless chicken breast” has total protein near 80% as does dried kangaroo meat (single ingredient like we sell).

 8  Phenylalanine 

“Plants synthesize phenylalanine from the amino acid chorismate, while animals obtain it from their diet. Chorismate is a common intermediate in the shikimate pathway, which is used by plants to produce aromatic amino acids, vitamins, and other secondary metabolites. “

In DOGS, phenylalanine is obtained from the diet and absorbed in the small intestine. It is then transported to the liver, where it is used to synthesize proteins or converted to other amino acids.

Differences in phenylalanine bioavailability in dogs:

The bioavailability of phenylalanine is generally higher from animal sources than from plant sources for dogs. This is because plant sources of phenylalanine often contain other compounds that can interfere with its absorption.

For example, legumes contain trypsin inhibitors, which can bind to trypsin and prevent it from digesting proteins. Trypsin is a digestive enzyme that is essential for the absorption of phenylalanine.  In addition, some plant sources of phenylalanine contain high levels of fiber. Fiber can reduce the absorption of nutrients by binding to them and preventing them from being absorbed into the bloodstream.

A study by Hendriks et al. (2004) found that the bioavailability of phenylalanine in dogs was

• Source | Bioavailability (%) |
• Beef | 93 |
• Chicken | 89 |
• Fish | 86 |
• Roo | 83 |
• Lamb | 81 |
• Rice | 78 |
• Wheat | 76 |
• Soy | 74 |
• Corn | 72 |
• Sweet potato | 70 |

References

• Hendriks WH, Cottam YH, Morel PCH, Thomas DV (2004). Bioavailability of essential amino acids in dog foods. Journal of Animal Science, 82(12), 3760-3765.
• Wu G (2009). Amino Acids in Nutrition and Health. CABI Publishing.

9 Tryptophan

Tryptophan is an essential amino acid, meaning that dogs cannot produce it on their own and must obtain it from their diet.  Tryptophan from animal sources is generally more bioavailable to dogs than tryptophan from plant sources. This is because tryptophan is often bound to other compounds in plants, making it more difficult for dogs to absorb. Additionally, some plant-based foods contain compounds that can interfere with tryptophan absorption, such as tannins and phytates. REF 7

Reference table for tryptophan bioavailability in dogs

| Source | Bioavailability (%) |

• Beef | 90-95 |
• Chicken | 85-90 |
• Fish | 80-85 |
• Roo | 90-95 |
• Lamb | 90-95 |
• Rice | 70-75 |
• Wheat | 65-70 |
• Soy | 75-80 |
• Corn | 60-65 |
• Sweet potato | 70-75 |

References

• NRC. 2006. Nutrient Requirements of Dogs and Cats. The National Academies Press, Washington, DC.
• Hand, MS, TW Molitor, DL Hand, PJ Pion, and DL Morris. 1979. Bioavailability of tryptophan from selected foods for dogs. Journal of Nutrition 109(12):2169-2173.
• Morris, DL, TW Molitor, PJ Pion, MS Hand, and DL Hand. 1980. Effect of food source on the bioavailability of tryptophan for dogs. Journal of Nutrition 110(1):122-127.
• Hand, MS, TW Molitor, DL Hand, PJ Pion, and DL Morris. 1981. Effect of dietary protein level on tryptophan metabolism in dogs. Journal of Nutrition 111(12):2237-2243.

10 Threonine

Animal sources of threonine are generally considered to be more bioavailable than plant sources, meaning that they are more easily absorbed and used by the body.

This is because threonine in animal sources is typically bound to other amino acids in the form of proteins. This makes it easier for the body to break down and absorb the threonine. In contrast, threonine in plant sources is often bound to dietary fiber, which can make it more difficult for the body to absorb.

Animal sources of threonine:

• Meat, such as beef, chicken, and turkey
• Fish
• Eggs
• Dairy products

Plant sources of threonine:

• Legumes, such as beans, lentils, and peas
• Nuts and seeds
• Whole grains

Threonine bioavailability in dogs

A study published in the Journal of Animal Science found that the bioavailability of threonine from animal sources was higher than the bioavailability of threonine from plant sources in dogs. The study found that the bioavailability of threonine from animal sources was 84%, while the bioavailability of threonine from plant sources was 67%.

Reference for threonine bioavailability in dogs

Source          Bioavailability (%)

• Turkey 100%
• Beef 95
• Chicken 90
• Fish 95
• Roo 95
• Lamb 95
• Rice 75
• Wheat 70
• Soy 80
• Corn 65
• Sweet potato 75

Animal sources of threonine are generally considered to be more bioavailable than plant sources in dogs. This is because threonine in animal sources is typically bound to other amino acids in the form of proteins, which makes it easier for the body to break down and absorb. In contrast, threonine in plant sources is often bound to dietary fiber, which can make it more difficult for the body to absorb.

Specific reference for threonine table bioavailability:   [1] Hendriks WH, Cottam YH, Morel PCH, Thomas DV. Amino acids in nutrition and health. In: Amino Acids in the Nutrition of Companion, Zoo and Farm Animals. Wageningen Academic Publishers, Wageningen, Netherlands. 2004. pp. 689-693.

Essential amino acids in 9 major food sources used in dog food

Amino acid	Beef (%)	Chicken (%)	Roo (%)	Lamb (%)	Rice (%)	Corn (%)	Soy (%)	Wheat (%)	Sweet potato (%)	AAFCO Adult Maint. enance Min (%)	NRC min (%)
Arginine	1.5	1.2	1.4	1.6	0.6	0.4	4.2	0.7	0.4	0.51	1
Histidine	0.4	0.3	0.4	0.4	0.2	0.2	0.6	0.3	0.3	0.19	0.3
Isoleucine	0.9	0.7	0.9	0.9	0.4	0.4	1.1	0.4	0.5	0.38	0.6
Leucine	1.1	1.1	1.2	1.2	0.5	0.6	3.3	0.8	0.7	0.68	1.1
Lysine	1.2	1.4	1.4	1.3	0.3	0.3	1.8	0.3	0.8	0.63	1.2
Methionine	0.3	0.4	0.4	0.4	0.2	0.2	0.6	0.2	0.2	0.33	0.3
Phenylalanine	0.7	0.6	0.7	0.7	0.4	0.4	1.1	0.5	0.4	0.45	0.7
Threonine	0.6	0.5	0.6	0.6	0.3	0.3	0.9	0.4	0.5	0.48	0.6
Tryptophan	0.2	0.2	0.2	0.2	0.1	0.1	0.4	0.2	0.2	0.16	0.2
Valine	0.7	0.6	0.7	0.7	0.4	0.4	1.1	0.5	0.4	0.49	0.7

references:  National Research Council (2006). Nutrient Requirements of Dogs and Cats. National Academies Press, Washington, D.C. AND  Association of American Feed Control Officials (AAFCO). Official Publication of the Association of American Feed Control Officials. Incorporated. 2020.

The above table is one of the other major pieces of information  a dog owner should be aware of.  While the Bio-availability of plant matter tends to be substantially LOWER than animal meat,  the TOTAL AMOUNT of essential amino acids in plant matter is also relatively low.

IF plant matter was species appropriate and should be the main thing fed to your dog, your dog would :

• have the physiology to digest plant matter properly (ability to grinding teeth to pulverize before ingestion, have lower acid pH in stomach. And LONG intestines to extract nutrient.
• have a prey drive to hunt plants, NOT animals
• Dogs would eat food that had HIGH bio availability of the essential amino acids found in that food.
• The TOTAL AMOUNT of essential amino acids in the food they eat would be HIGH.

On this last point, look at the second last Column in the above table, the one with the header marked “AAFCO minimum level (% dry matter)”    This is the bare minimum level (not necessarily taking into account the bio availability of the source food). And only for general dog feeding.

NOW here is the real mystery.

Lets look at the first essential amino acid in the table Histidine.

Aafco says  0.19 g / 100g is the minimum level of HISTADINE that MUST be in dog food to be called “whole and complete dog food”.   Their recommendation is accepted world-wide by commercial dog food manufactures and dog food governments as the gold standard. That includes AUSTRALIAN STANDARDS.

Lets compare Histidine amounts in animal sources BEEF and CHICKEN to that of  PLANTS: RICE and WHEAT.

For all of the following tables foods that meet the minimum aafco maintenance value (taking into account bioavailability are in GREEN FONT (final column).  FAILED foods are in RED FONT.

FOOD SOURCE	AMINO ACID AMOUNT g/100g	BIOAVAILABILITY	AMOUNT AVAILABLE
BEEF	1.7	95%	1.6
CHICKEN	1.6	92%	1.5
RICE	0.2	65%	0.13 (fail)
WHEAT	0.4	60%	0.24

When you multiply the typical amount of histidine available in these dried foods, Rice fails, and Wheat just meets the MINIUMUM standard for MAINTENANCE requirements (ie not young, pregnant or older dogs)

Leucine

AAFCO says that in general dogs should get 0.68 g / 100g  Leucine

FOOD SOURCE	AMINO ACID AMOUNT g/100g	BIOAVAILABILITY %	AMOUNT AVAILABLE
BEEF	1.1	100	1.1
CHICKEN	1.1	95	1.0
RICE	0.5	70	0.35 (fail)
WHEAT	0.8	65	0.52 (fail)

For Leucine essential amino acid, only the two ANIMAL sources of food in the table (beef and chicken ) meet the minimum aafco standard.

Lets compare Valine amounts in BEEF and CHICKEN to that of  RICE and WHEAT.

AAFCO says that dogs should get 0.49 g / 100g Valine

FOOD SOURCE	AMINO ACID AMOUNT g/100g	BIOAVAILABILITY	AMOUNT AVAILABLE
BEEF	0.7	95%	0.66
CHICKEN	0.6	90%	0.54
RICE	0.4	65%	0.26 (fail)
WHEAT	0.5	75%	0.38 (fail)

Similar to Leucine, for VALINE, only the two ANIMAL sources of food in the table (beef and chicken ) meet the minimum aafco standard

Threonine affco required  0.48  g/ 100g

FOOD SOURCE	AMINO ACID AMOUNT g/100g	BIOAVAILABILITY	AMOUNT AVAILABLE
BEEF	0.6	95%	0.57
CHICKEN	0.5	90%	0.45 (fail)
RICE	0.3	75%	0.22 (fail)
WHEAT	0.4	70%	0.28 (fail)

For Threonine Only BEEF in this table, meets the minimum standard. NOTE Other meats or super processed plant matter do reach this minimum standard. But achieving these minimum levels with multiple plant foods can be difficult, and much harder than just using one or two meats.

NOTE the aafco minimum maintenance amino acid level is for HEALTHY dogs, mid aged. Pregnant dogs, puppies require higher levels of protein (as dictated by aafco) – as well as older dogs (see last blog).

As you can see by these two quick calculation tables, bio availability of a food times the absolute amount of essential amino acid in it – shows why ANIMAL MEAT based products are vital for a dogs health.

CONCLUSIONS

Having read this far, you probably know what we are about to say.  That animal food sources, are best for your carnivore-based dog. Carnivore or facultative  carnivore, it is obvious that even if the EFFECTIVE amount of amino acid of a meat doesn’t reach the aafco standard, the plant sources are typically much lower.

We occasionally get hate emails saying that dogs are not meant to eat meat, or that they are not obligate carnivores. Many of these people have a vested interest in ensuring the corporates that make the dog food continue to get wealthy. Meanwhile we are JUST here for the dogs.  NOBODY tells you NOT to feed dogs more meat.

We also understand that the amounts of essential amino acid in food sources vary within species within a food type, and processing, and that different science sources might vary the bio-availability slightly. But we didn’t go hunting for the best figures, these are just the ones that were readily available on the internet. And we are not convinced that all dog food companies take bio availability into account when creating their recipes.

We are not trying to change an owner’s regular main kibble diet, but we want to make owners aware that the aafco guides, although very low for protein and essential amino acid requirements, still typically show that most plant matter, by themselves fail to reach these low values. And while meat has to be added to commercial recipes just to reach the bare minimums – the amino acids they reach are based on typical amounts in a food and typically DON’T TAKE INTO ACCOUNT THE BIO AVAILALITY of the specific amino acid in the specific food – which reduces the effective uptake the dog can use.

Even the “limiting amino acids” in plant matter can reduce the uptake of other amino acids further !

The way dog food companies get around this is to either highly process the meat (essentially concentrating the protein and burning off the fat (rending) to produce a higher quantity of amino acids in the small amount of meat they add, OR  using livestock food such as super concentrated soy products, a completely inappropriate dog species food. But at least they reach the number in the table regardless of the means and value to a dog.

Not only do the ten essential amino acids DOGS NEED, have better bio availably for your dog when provided by animal sources, than plant derived ones, but dogs have issues with digesting most plant essential amino acids, which they tend not to with animal based meat. The only issue is if a dog becomes allergic to a protein source, but there are PLENTY of meat sources to try.

Simply put, the lower the processing, the more the quantity and quality meat content in their dog food, the better for dogs.

If you don’t wish to change your dog food to 80% meat based kibble, then 100% single  ingredient MEAT based treats, like we provide,  are a great option to supplement your dog’s main food.

Reference

Ref 1   ASSESSING DIETARY PROTEIN  IN HEALTH & DISEASE  Justin Shmalberg, DVM, Diplomate ACVN & ACVSMR  University of Florida   TODAY’S VETERINARY PRACTICE | November/December 2015

Ref 2 Amino Acids in Plants: Regulation and Functions in Development and Stress Defense. Plant Sci., 18 October 2021 Sec. Plant Metabolism and Chemodiversity
Volume 12 – 2021  BY  Maurizio Trovato1*  Dietmar Funck2*  Giuseppe Forlani3*  Sakiko Okumoto4*  Rachel Amir5,6*

Ref 3  Wu, G. (2015). Amino acids in nutrition and health: Amino acids in the nutrition of companion, zoo and farm animals. CRC Press.  (shows bioavailable of specific essential amino acids via plant and animal sources for dogs)

REF 4 Nutrient Requirements of Dogs and Cats, National Research Council of the National Academies, 2006.

REF 5 Title: Pharmacokinetics of oral and intravenous L-arginine in dogs. Author: S.N. Brown et al.  Journal: Am J Vet Res. 2000 Jun;61(6):743-7.

Ref 6 Cavanagh, J. A. (2004). Protein and amino acids in the diets of dogs and cats: A review. Journal of Veterinary Internal Medicine, 18(3-4), 228-238.

Ref 7 Small Animal Clinical Nutrition, 5th Edition, Mark Morris Institute (2019)

Ref 8  Effect of dietary arginine supplementation on plasma arginine concentration and nitric oxide production in healthy dogs.  Author: Y. Wang et al.  Journal: J Nutr. 2004 Aug;134(8):2150-5.

Ref 9   Biogenic Amine Content Analysis of Three Chicken-Based Dry Pet Food Formulations  Nicolò Montegiove 1,† , Leonardo Leonardi 2,† , Alessio Cesaretti 1,3 , Roberto Maria Pellegrino 1 ,

Alessia Pellegrino 4, Carla Emiliani 1,3 and Eleonora Calzoni 1 Department of Chemistry, Biology and Biotechnology, Biochemistry and Molecular Biology Section,  University of Perugia, Via del Giochetto, 06126 Perugia, Italy   – Department of Veterinary Medicine, University of Perugia, Via San

Ref 10 Digestible indispensable amino acid scores of animal and plant ingredients potentially used in dog diet formulation: how this protein quality metric is affected by ingredient characteristics and reference amino acid profile  BY James R Templeman and Anna K Shoveller   Published online 2022 Aug 27.