Beware: “Crude Protein” Doesn’t Mean What You Think!

Pet Food Bowl

Pet Food BowlIt came as a big surprise to me to learn that the words “crude protein” that you see on all bags of pet food — that you are carefully looking for on the label — don’t really have anything directly to do with what we think of as being protein — meat, fish or poultry. This was a distressing discovery since as a “pet foodie,” my number one concern is protein and how much of it is in there when I judge a pet food.

We all know from practical experience that protein is the most expensive part of any meal, whether it is for people or pets, so we want to assure ourselves that the pet food we are choosing is really full of a good protein source.

We all think of protein as one of the “building blocks of life” and recognize it as a vitally important ingredient in our food, and that of our pets. We also know that the quality of the protein you eat matters, and for years I had this misconception that the words “crude protein” referred to protein in its most basic form — as the absolute value of protein that was in the food, the “bottom line,” the percentage of protein you could trust this food to deliver to your pet. Boy was I wrong! Guess what “crude protein” is actually a measurement of? The nitrogen content of the food!

How did this happen?! Had I been bamboozled? Foolish? Had I been misled by perplexing terminology and then misled any of the readers or listeners who were depending on me to lead them to good decisions on their pet’s nutrition? Or was I going on wishful assumptions instead of easily discovered facts?

What is the Take Away Message? “Crude protein” is a measurement of nitrogen, which is a roundabout way to assess the presence of protein in a food, but not the actual protein you might be imagining, as I did. And “crude protein” does not reflect on the quality of that protein, in any case. Which leads me to the conclusion that the best choice you can make for your own peace of mind — and for your pet’s nutritional health — is to put your faith and your pet’s well-being in the hands of a company like Halo that states right out: made with real meat. The protein you are seeking is the protein you will get, not the nitrogen you will receive as a function of “crude protein” assessment!

What it boils down to is that “not all crude protein is created equal. It’s what I love about Halo — they are proud about that aspect of their dog food ingredients that celebrates the highest quality protein source: real meat (or fish, or chicken)!

To learn more, I turned to the renowned veterinary nutritionist Sean Delaney, who happens to be my co-host on my weekly radio show PET FOOD ADVISORS on the Radio Pet Lady Network ( Our show is basically an education in how pet food is made, what various ingredients mean and why they are in pet food, and how to eliminate emotion and use your common sense when making food choices for your pets (or yourself). Dr. Delaney co-edited the only independent textbook on nutrition used in veterinary schools; I bought my copy of Applied Veterinary Clinical Nutrition (Wiley Blackwell) (not the most catchy title, I admit!) and I love having it as a reference book to accompany our weekly show, which is like getting a course in veterinary nutrition from a very fun and smart professor (which he was, actually, for ten years at U.C. Davis School of Veterinary Medicine). I quote from that book:

“There are several ways to assess an ingredient’s or a food’s protein content. The typically required and reported crude protein value does not give any indication of how well a food will meet a dog’s or cat’s protein or amino acid requirements, although higher crude protein values are often perceived as better. In fact, crude protein doesn’t even represent protein content directly, but rather nitrogen content. Then, a standard equation of the nitrogen percentage in the food times 6.25 is used to calculate crude protein. This fact was at the root of the major pet food recall of 2007 where wheat flour was apparently being “spiked” with a cheap nitrogen-rich ingredient — melamine — that formed crystals within the kidney when in the presence of a related chemical — cyanuric acid — resulting in renal failure. Therefore, crude protein is really an indirect measurement of protein quantity and does not provide any information about protein quality. Ideally, a measure of protein quality should provide some insight as to how well a particular source of protein meets the protein and amino acid requirements of a particular species.  In general, the higher the quality of the protein, the more available essential amino acids the protein source provides.”

photo credit: Mr. T in DC via photopin cc