As Fed vs Dry Matter Basis (DMB) in Dog Food
Learn how to accurately compare nutritional values between kibble, canned, and fresh foods by understanding moisture content and dry matter calculations.
Introduction
When comparing dog foods, the numbers on the label can be deceiving. A kibble showing 25% protein seems far superior to a canned food listing just 8% protein. But this comparison is fundamentally flawed. The difference? Water content. All nutritional values on pet food labels are shown "as fed" – meaning they include whatever moisture is in the food. Since kibble contains about 10% water while canned food can be 75% water, you're not comparing like with like. Understanding the difference between "as fed" and "dry matter basis" (DMB) is essential for making informed decisions about your dog's nutrition, especially when comparing different food formats or evaluating homemade recipes against commercial options.
Quick Definition
**As Fed**: Nutritional values as the food is packaged and served, including all water content. **Dry Matter Basis (DMB)**: Nutritional values calculated as if all moisture were removed, allowing true comparison between any food types.
The Moisture Problem
Different food formats contain vastly different amounts of water: | Food Type | Typical Moisture Content | |-----------|-------------------------| | Kibble/Dry Food | 8-12% | | Semi-Moist Food | 25-35% | | Fresh/Raw Food | 60-75% | | Canned/Wet Food | 75-85% | This moisture dramatically affects how nutrient percentages appear on labels. Consider a canned food with 8% protein and 78% moisture versus a kibble with 26% protein and 10% moisture. The canned food appears to have far less protein – but does it really?
Why Dry Matter Matters
By removing the "water variable" from the equation, dry matter basis creates a level playing field for nutritional comparison. Think of it this way: if you could magically remove all the water from both foods and weigh the remaining nutrients, you'd be comparing the actual nutritional density of each food – not just how diluted it is. This is particularly important when: - Comparing wet food to dry food - Evaluating fresh or raw diets against kibble - Assessing whether a food meets nutritional standards (like FEDIAF guidelines) - Formulating homemade recipes to match commercial standards
The DMB Calculation
Converting from as-fed to dry matter basis requires a simple two-step calculation: **Step 1: Calculate Dry Matter Percentage** ``` Dry Matter % = 100 - Moisture % ``` **Step 2: Convert to Dry Matter Basis** ``` DMB % = (As-Fed % ÷ Dry Matter %) × 100 ``` **Full Worked Example:** Let's convert that 8% protein canned food (78% moisture) to DMB: 1. Dry Matter = 100 - 78 = **22%** 2. Protein DMB = (8 ÷ 22) × 100 = **36.4% protein** And the 26% protein kibble (10% moisture): 1. Dry Matter = 100 - 10 = **90%** 2. Protein DMB = (26 ÷ 90) × 100 = **28.9% protein** The canned food actually contains MORE protein on a dry matter basis!
Quick Calculation Shortcut
**To convert any as-fed value to DMB:** 1. Find the moisture % on the label 2. Subtract from 100 to get dry matter % 3. Divide the nutrient % by the dry matter % 4. Multiply by 100 **Example**: 10% fat in a food with 75% moisture: 10 ÷ (100-75) × 100 = 10 ÷ 25 × 100 = **40% fat DMB**
Practical Comparison Table
Here's how three different foods with seemingly different protein levels actually compare: | Metric | Kibble | Canned | Fresh | |--------|--------|--------|-------| | Protein (As Fed) | 26% | 10% | 12% | | Moisture | 10% | 78% | 70% | | Dry Matter | 90% | 22% | 30% | | **Protein (DMB)** | **28.9%** | **45.5%** | **40%** | The canned and fresh foods, despite their lower as-fed protein percentages, actually provide significantly MORE protein per unit of dry matter than the kibble. This doesn't make one format "better" than another – it simply means you need to look beyond the label percentages to understand what you're actually feeding.
How Our Recipes Display Values
Throughout our recipe library, we display nutritional values in both formats: - **As-fed values** help you understand what's in each serving as prepared - **Dry matter values** allow accurate comparison against FEDIAF nutritional guidelines and other foods Our nutrition analysis automatically calculates both, so you can confidently assess whether a recipe meets your dog's nutritional needs regardless of its moisture content.