The Controversy Over Animal By-Products


What are animal by-products?

The Association of American Feed Control Officials (AAFCO) defines animal by-products as “the rendered product from animal tissues.” The association further specifies that animal by-products encompass individual rendered animal tissue products that cannot meet the criteria for more specific classification.

In other words, animal by-products contain rendered animal tissue which cannot be linked to any specific part of an animal(s). It may include livers, lungs, brains, kidneys, intestines, etc.

Why are animal by-products controversial?

Animal by-products are not inherently undesirable ingredients. In fact, studies on poultry by-products have not shown any significant difference between the nutritional composition of poultry by-product meals and regular poultry meals.

Studies have also shown that there is no significant discrepancy between the digestibility of poultry by-product meals and regular poultry meals.

Given this information, you may be puzzled by the controversy surrounding animal by-products. The controversy mostly stems from the following issues:

  • The quality of the by-products
  • The motivation behind their use in pet food

Animal by-products can contain animal parts that are unfit for human consumption. For example, parts of the slaughtered animal that are not refrigerated immediately after slaughter are acceptable additions in animal by-products destined for pet food. In addition, by-products are typically very inexpensive when compared to clearly identifiable ingredients such as chicken liver or turkey gizzards.

Are all animal by-products the same?

Absolutely not. There is an important distinction that can be made between “named” and “anonymous/generic” by-products.

Ingredients for which the source animal is clearly specified (such as chicken by-products) is superior to generic ingredients (such as meat by-product). Unlike “named” by-products, “generic” by-products can contain road kill, diseased livestock, euthanized pets, and other undesirable additions.

Final Thoughts

Animal by-products can be an acceptable addition for both dog and cat food products. However, consumers should always ensure that the product does not contain generic by-products.

Food Finder Tips

PawDiet’s pet food finder can help you quickly find products without animal by-products or more spicificly without generic/anonymous animal by-products.

Products Without Any Animal By-Products

  1. Open PawDiet’s food finder
  2. Select: Ingredient Quality ⇒ Free of Animal By-Products

Products Without Any Generic/Anonymous Animal By-Products

  1. Open PawDiet’s food finder
  2. Select: Ingredient Quality ⇒ Free of Anonymous Meats

Note: This selection will also exclude other generic/anonymous animal products (such as meat and bone meal). If you’d like more control, use the Ingredient Filtering option under Advanced Settings.

References & Notes

  1. United States. Association of American Feed Control Officials. AAFCO Official Publication, 2015. Print.

  2. Watson, Hillary. “Poultry Meal vs. Poultry ByProduct Meal“. Dogs in Canada Magazine, January 2016.