Have you ever been at your local pet food supply store and someone mentions that commercial raw food has more protein than kibble? So, you wander over and check out the protein content on the guaranteed analysis on the raw and it states 13%, but that bag of kibble you were just looking at states 32%.
Huh? Say what? Are you confused? Are you internally wondering where they learned to read as clearly the guaranteed analyses state differently?
They are actually correct. But why?
Moisture content. We’ll explain.
When comparing the variety of pet food types – such as canned, dehydrated, kibble and raw – you should refer to the dry matter basis.
‘Dry matter basis’ sounds more complicated than it is.
The definition is, “The dry matter basis assumes no water is present — i.e. 100 percent dry matter.”
Please take the definition at face value; there is nothing to read into. There is NO underlying complexity.
Guaranteed analysis does not contain the food’s pre-processing moisture content, which can change dramatically during processing, depending upon the type of food.
Let’s look into the various food types and how they are processed:
Kibble is highly processed compared to moisture-rich foods. It goes through an extrusion process – the same process as human cereals – to become shelf stable so it does not rot or become moldy from moisture. The high temperatures are necessary for extrusion, but inactivate or destroy a certain amount of the protein.
Dehydrated foods use warm air to evaporate a food’s water content. A benefit of dehydration is that it diminishes the growth of pathogens such as bacteria, yeasts and molds without adding chemicals, since pathogens need water to grow. With dehydrated food, you need to reconstitute it.
Meats contained in cans are less processed and thus tend to be closer to their natural state than those found in kibble. Canned foods are pressure sterilized and sealed. The contents are naturally protected from rancidity, so manufacturers don’t need to add potentially harmful chemical preservatives.
Raw food is found in the freezer section. A raw commercial diet is literally uncooked food and the moisture has barely been removed from the meat. Major commercial raw manufacturers incorporate kill steps to destroy pathogens while creating the least impact on the food’s enzymes, proteins and other nutrients.
Think about it in terms of human food. Beef jerky is dried, whereas a fresh steak is juicy. The steak has more moisture.
Homework: Converting to Dry Matter
So, you need to convert the guaranteed analysis into dry matter basis.
Fortunately, calculating Dry Matter Basis is quite simple once you get the hang of it. Here’s how in two simple steps:
Subtract the percent of the food’s listed percent of moisture from 100% to determine the food’s percentage of dry matter (DM). For example, a kibble containing 8% moisture will contain 92% DM.
100 – Percent of Moisture Listed on the Back of Package = Y
Take the percentage of crude protein listed under the Guaranteed Analysis and divide that number by the DM number you determined in Step 1.
Crude Protein Guaranteed Analysis ÷ Y = Dry Matter Basis
We’ll Show You
Below we have 4 only-turkey, grain free diets: kibble, raw, dehydrated and canned.
|Subtract Moisture from 100 to Determine Dry Matter||100 – 10 = 90||100 – 74 = 26||100 – 7 = 93||100 – 75 = 25|
|Dry Matter Result||90||26||93||25|
|Guaranteed Analysis Crude Protein||25%||13%||30%||10.5%|
|Divide Guaranteed Analysis Crude Protein by Dry Matter||25 / 90 = 28||13 / 26 = 50||30 / 93 = 32||10.5 / 25 = 42|
|Protein on Dry Matter Basis||28%||50%||32%||42%|
As you can see from the numbers, kibble barely changes. So, if you are comparing kibble-to-kibble, this should be OK. However, there is definitely more to consider when choosing a pet food. Dr. Ryan Yamka recently gave an excellent presentation on product label claims and what’s the truth on the back of the bag. We suggest watching