How useful are Guaranteed Analysis numbers?
You see them on every bag and can of pet food. You hear pet owners toss them around as if they are the best indication of comparative quality.
But what do they really tell us?
GA numbers can indeed be used to compare dog foods. But there is a bit more to understanding their value than just comparing the numbers.
Let’s take a look at what those numbers actually represent, and what they do not.
Meaningful Measurements or Crude Estimates?
When you think of Guaranteed Analysis numbers on dog food, you’ll most likely think of measurements of Protein, Fat, Fiber, and Moisture. And, if that was truly what the GA numbers represented, it would be a simple exercise to use them to compare dog foods in a meaningful way.
But, as we saw with ingredients, things are not always as simple as they appear.
Take a closer look at that GA label. It doesn’t actually say Protein, does it? It says Crude Protein.
Nor does it reflect an exact measurement. It reflects a Minimum measurement of Crude Protein and Crude Fat. And it reflects a Maximum Value of Crude Fiber and Crude Moisture.
Minimum and Maximum? Crude? No longer simple and meaningful information for comparison.
Here’s why. When a nutrient is measured in a Crude form, is represents an estimate of that nutrient contained in an ingredient or product. It is not an exact measurement. More importantly, it provides no information relating to quality.
Combine that with the use of minimum and maximum values used in GA numbers, and you are left with a huge range of where the actual numbers fall.
When you see a Crude Protein listing of (not less than) 28%, it is entirely possible that the product contains 40% Crude Protein. Or 29% Crude Protein. Which may actually test out as 10% available (usable) Protein. Or 25% Protein.
We just don’t know.
What good are Guaranteed Analysis numbers?
So why even look at GA numbers? Good question!
They do not provide an accurate measurement of available Protein, Fat, Fiber or Moisture. They do, however, provide an relatively consistent comparative standard across all brands of pet food.
Unfortunately, even this standard can be misleading, since quality levels of ingredients vary widely from brand to brand. And, since quality affects the digestibility and usability of nutrients, we’re still left guessing.
You can choose a “higher protein” food based on the GA numbers, but you’ll never know how close that GA number is to what is actually available in the product.
For our purposes- choosing the best pet food- they play a very minor role.