What Is Digestibility?

When we think about dog food, we tend to believe that the most important feature of a food is its ingredients. This is partly true, since ingredients influence the final nutritional quality of the food to some extent. However, ingredients are not the deciding factor: what really makes a food better or worse is the digestibility it offers.

Because most people are not very familiar with what digestibility is and why it matters, this feature is often overlooked, even though it is, or should be, vital when choosing one food over another. In fact, the prestigious World Small Animal Veterinary Association (WSAVA) states: “in general, ingredients do not describe the nutritional quality of a food; the digestibility and bioavailability of nutrients are what matter most, and they are what guarantee a pet's nutritional requirements.”

When it comes to dog food, digestibility is everything, because it determines, as a percentage, how much of the food is absorbed by the body. Simply put, you could find a dog food brand made with the best and finest ingredients, but if its formulation does not achieve a high percentage of digestibility, those ingredients will not be absorbed by the dog's body—which literally means that the food will be eliminated as quickly as it went in.

That is why it is so important to understand what digestibility is and how it is measured: according to the Association of American Feed Control Officials (AAFCO), the digestibility of a processed dog food can range from 10% to 100% depending on the diet or combination of ingredients, with 80% being the ideal required for maintenance.

But before going on with numbers and percentages, we need to fully understand what digestibility is.

What is digestibility?

Digestibility is a criterion that determines the nutritional value of a food and measures how well it is utilized—that is, the proportion of nutrients the dog's body uses for all its vital processes.

Books on canine nutrition, such as Dog Food Logic, place great emphasis on choosing highly digestible foods, such as super premium foods like NUPEC^® (MR), whose HIGH TECH formula offers over 90% digestibility. Besides nourishing the dog, this provides very tangible visible benefits such as solid, well-formed, smaller and less frequent stools, as well as low gas levels.

Sources:

1. AAFCO Dog and Cat Food Nutrient Profiles https://www.aafco.org/Portals/0/SiteContent/Regulatory/Committees/Pet-Food/Reports/Pet_Food_Report_2013_Midyear-Proposed_Revisions_to_AAFCO_Nutrient_Profiles.pdf
2. Digestibility of Pet Foods R. G. Brown Nutrition Consultant CVMA Pet Food Certification
3. Protein and amino acid bioavailability of extruded dog food with protein meals of different quality using growing mink (Neovison vison) as a model. Journal of Animal Science 2016; 94:3796-3804.
4. Raw, mechanically separated chicken meat and salmon protein hydrolysate as protein sources in extruded dog food: Effect on protein and amino acid digestibility. Animal Physiology and Animal Nutrition 2017; 101:323-331.2.