How Soy Works in Pet Food



Soy is a staple ingredient in many plant-based formulas for cats and dogs. In fact, soy is considered to be the best protein source for domestic animals, due to two important factors: availability of essential amino-acids and their excellent digestibility.

Excellent source of essential amino-acids

Of all plant protein sources, soy is considered the best ingredient for dogs and cats from the amino-acid perspective. It has a high protein content as well as a well-balanced amino acid profile. ¹

Table below depicts protein concentration (%) and essential amino acid composition (g/100g protein) in soy (soy protein concentrate) versus meat by-product (poultry). Nutritional requirements of dogs and cats (%) are also included. ^2,3

Table 1. Amino-Acid Comparison in Soy and Meat By-product vs. Requirement for Dogs and Cats ^2,3

We can see from this data that concentration of most essential amino-acids in soy is comparable to those in meat by-product – a commonly used ingredient in commercial pet foods. Combining soy with other plant-based ingredients creates a balanced amino-acid profile that easily meets nutritional requirements for cats and dogs.

Easily digestible

Effectiveness, or ‘quality’, of protein is affected by two major factors:

• concentration (quantity) of essential amino acids
• digestibility (absorption or bioavailability) of each essential amino acid.

In other words, a good protein source will not only contain higher concentration of essential amino acids, but will also ensure easy digestion of these amino acids in the intestine of an animal. Soy ingredients boast high digestibility ratings of essential amino acids.

In fact! digestibility of soy proteins is overall comparable to those of meat proteins, as has been found in several research studies ^4,5 .

One study even demonstrated that soy protein concentrate had higher apparent digestibility percentages for most essential amino acids, compared to poultry meal (see Table 2). ⁶

Table 2. Apparent ileal digestibility (%) of crude protein and amino acids in dogs ⁶

All this research suggests that soy ranks highly on both essential amino acid concentration and digestibility, which make it an excellent alternative to meat protein and an important ingredient in plant-based pet foods.

Non-GMO soy

Some people are concerned with feeding genetically modified products to their companion animals. As a result they try to choose non-GMO ingredients whenever possible.

Vecado offers products that contain high-quality, non-GMO soy.

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1. Dodd, S.A.S., Adolphe, J.L., Verbrugghe, A. Plant-Based Diets for Dogs. Timely Topics in Nutrition. 253:11, 2018.
2. NRC, 2018. Tenth revised edition. National Research Council, National Academy Press, Washington, DC, USA.
3. Association of American Feed Control Officials (AAFCO), 2004. link
4. Huber, T.L., LaFlamme, D. Comer, K.M. and Anderson, W.H., 1994. Nutrient digestion of dry dog foods containing plant and animal proteins. Canine Pract 19:11-13.
5. Zuo, Y., Fahey, Jr., G.C., Merchen, N.R. and Bajjalieh, N.L., 1996. Digestion responses to low oligosaccharide soybean meal by ileally-cannulated dogs. J Anim Sci 74, 2441-2449.
6. Clapper, G.M., Grieshop, C.M., Merchen, N.R., Russett, J.C., Brent, J.L. and Fahey, G.C. Jr. 2001. Ileal and total tract nutrient digestibilities and fecal characteristics of dogs as affected by soyabean protein inclusion in dry extruded diets. J Anim Sci 79:1523-1532.