For those of you who are interested in your pet's nutrition!
Generally speaking, pet owners focus on just a few of these eight areas, including the guaranteed analysis, the ingredient list, and nutritional adequacy information.
The guaranteed analysis on a pet food label lists the minimum percentage of crude protein and fat contained in the product, and the maximum percentage of crude fiber and moisture.
The crude protein percentage indicates the total protein content of the food and not necessarily the amount of protein that is digestible. The actual amount of protein your pet’s body will be able to use depends on its source and quality.
The crude fat percentage is an estimate of the lipid content of the food; crude fiber is an estimate of the insoluble fiber content. As with crude protein, these percentages are not an indication of the quality or digestibility of the fat and fiber contained in the pet food.
Since the guaranteed analysis on most commercial pet foods doesn’t give an accurate picture of the amount of each nutrient, we have to do a little math to understand what’s really going on.
Here are the guaranteed analyses for a high quality and poor quality dog food:
Raw, Sold Frozen
Guaranteed Analysis (as fed)
Protein (not less than) 12%
Fat (not less than) 8%
Moisture (not more than) 71%
Carbohydrate (not less than) 3.5%
Fiber (not more than) 0.5%
'Premium' Dry Dog Food
Crude Protein (min) 25%
Crude Fat (min) 10%
Moisture (max) 14%
Crude Fiber (max) 4%
At first glance, it appears the dry dog food has a much higher amount of protein than the raw food, and slightly more fat. But to accurately compare the two foods, we have to convert the ingredients to dry matter using the following formula:
100 Percent - Percent Moisture = Percent Dry Matter (DM)
Using this formula, we can determine the percent dry matter (DM) of each food as follows:
Raw food has 71% moisture
100% – 71% = 29%
The raw food is 29% DM
Dry food has 14% moisture
100% – 14% = 86%
The dry food is 86% DM
Now that we know the dry matter content of each food, we can compare the true protein amounts with this formula:
Percent Protein / Percent DM = Percent Protein on a DM Basis
Using this formula, we can determine the percent protein of each food as follows:
Raw food: 12% protein, 29% DM
12% / 29% = 41%
Raw food has 41% DM protein
Dry food: 25% protein, 86% DM
25% / 86% = 29%
Dry food has 29% DM protein
You can use the same calculations to compare the other guaranteed analysis ingredients on a DM basis as follows:
Raw food: 8% fat
8% / 29% = 28%
Raw food has 28% DM fat
Dry food: 10% fat
10% / 86% = 12%
Dry food has 12% DM fat
Raw food: .5% fiber
.5% / 29% = .02%
Raw food has .02% DM fiber
Dry food: 4% fiber
4% / 86% = .05% fiber
Dry food has .05% DM fiber
As you can see by this apples-to-apples comparison, the raw food has significantly higher percentages of the three most important pet food ingredients: protein, fat, and moisture.
As many of you are aware, the ingredient list on pet food labels has a specific hierarchy. Per AAFCO guidelines, ingredients must be listed in descending order by weight, and must be listed by their common or usual name. In addition, most of the primary ingredients will have a corresponding definition in the AAFCO Official Publication.
But here’s where it gets confusing. The weight of each ingredient is calculated before moisture is removed. Animal meat weighs considerably more before it is processed to remove all the moisture. This is how pet food manufacturers can list an animal protein as the first ingredient in grain-based pet foods. Once the moisture is removed from the meat, a re-weighing of the ingredients would reveal a single grain or mixture of grains to be the primary ingredient – not animal protein.
This method of weighing and listing ingredients makes it impossible to tell which proportions of nutrients are derived from each ingredient. It’s also impossible to tell the quality and digestibility of the food from the ingredient list.
Using the same foods from the guaranteed analysis example above, look at the stunning difference in ingredient lists between the two. Which would you prefer to feed your canine companion?
Ingredients (Raw Dog Food) :
Free-Range Meat = 69%
chicken meat including bone, chicken gizzards, chicken hearts and chicken livers
Organic Vegetables = 29.3%
carrots, squash, yams, zucchini, celery, romaine, parsley, apple cider vinegar
Special Nutrient Mix = 1.7%
kelp, sea salt, inulin, zinc, copper and iron amino acid chelates, vitamin E
Ingredients (“Premium” Dry Dog Food) :
Ground yellow corn, corn gluten meal, whole wheat flour, animal fat preserved with mixed-tocopherols (form of Vitamin E), soy protein concentrate, soy flour, water, rice flour, pearled barley, sugar, tricalcium phosphate, propylene glycol, animal digest, dicalcium phosphate, salt, phosphoric acid, sorbic acid (a preservative), calcium carbonate, potassium chloride, L-Lysine monohydrochloride, dried spinach, dried apples, dried sweet potatoes, choline chloride, calcium propionate (a preservative), added color (Red 40, Yellow 5, Blue 2, Yellow 6), Vitamin E supplement, zinc sulfate, ferrous sulfate, manganese sulfate, niacin, Vitamin A supplement, copper sulfate, Vitamin B-12 supplement, DL-Methionine, calcium pantothenate, thiamine mononitrate, garlic oil, pyridoxine hydrochloride, riboflavin supplement, Vitamin D-3 supplement, calcium iodate, menadione sodium bisulfite complex (source of Vitamin K activity), folic acid, biotin, sodium selenite