If you see "crude" on your pup's dog food label, it's not because his food is immature or vulgar. Found in the guaranteed analysis section of the dog food label, crude protein, fat and fiber tells how much of each nutrient is in his food, but nothing about its quality.
The "crude protein" in Sammy's food refers to an estimate of the total amount of protein in his diet, based on how much nitrogen it contains. You may be tempted to assume the crude protein percentage is based on the amount of animal protein contained in your pup's food; however, it reflects the amount of all protein, regardless of its source. It doesn't indicate the type, quality or digestibility of the protein, so Sammy's food could contain chicken breasts, chicken feet or soy.
Sammy needs fat to aid in the absorption, storage and transport of fat-soluble vitamins and provide him with vital fatty acids. Crude fat content is measured by dissolving the ingredients in a solvent, evaporating the solvent and analyzing the leftovers. Crude fat is an estimate of the amount of fat in Sammy's diet before he metabolizes his food -- the fat portion of the energy he's about to burn.
Fiber helps Sammy's gastrointestinal health and is defined as edible parts of plants or similar carbohydrates that resist digestion and absorption in the small intestine and ferment in the large intestine. Crude protein is determined by extracting the components of fiber to estimate the food's fiber level.
Adding It Up
A dog's nutritional requirements depend on his age, breed, activity level and health. Generally, puppies require 22 percent protein in their diet, compared to 18 percent for an adult dog. Dogs require less fat than protein, and commercial pet foods reflect this, containing anywhere from 5 to 15 percent fat for adult dogs and 8 to 20 percent for puppies. Usually, about 4 percent of Sammy's diet should be fiber. Your vet can let you know if your pup has special nutritional needs. A look at the guaranteed analysis on his dog food label will let you know if you're on the right track.