Barley

Barley is grown and harvested as a food and feed grain. Mills dry and grind the kernels for use in dog food. Brewers' spent grain is a separate leftover from making beer.^1,6

1. 01 // Source Barley kernels Mature kernels come from the harvested crop; the grain is dried before storage.
2. 02 // Process Threshed and stored Threshing separates kernels from the stalks, and dry storage keeps the grain usable.
3. 03 // Process Ground Milling breaks the hard kernels, exposing starch that cooks during kibble extrusion.
4. 04 // Output Barley or meal Dry kernels or ground barley reach the kibble plant, where the recipe is mixed and cooked.

1. 01

   Supplies cooked starch

   Grinding and extrusion make barley starch accessible to digestive enzymes. In a dog trial, starch from every tested extruded grain flour diet was almost completely digested.^1,6

2. 02

   Adds grain fiber

   Barley brings fiber along with starch, giving formulators another way to set the recipe's fiber level. That does not mean it will firm a dog's stool.^2,5

3. 03

   Offers bulk grain supply

   Barley is a feed crop that competes with wheat and corn. Manufacturers can buy it through the grain supply chain as another bulk starch option when balancing cost and availability.⁶

How much Dog studies tested diets with 25% barley and diets with 10 to 40%; an extruded diet above 50% produced looser stools.^1,2,10

1. Brands say

   Barley gives dogs usable energy

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   Across 6 extruded flour diets, starch digestion exceeded 99%. A separate diet containing 25% barley had 83.85% dry matter digestibility. Barley supplies usable energy, although its fiber and the rest of the recipe affect total digestibility.^1,2

2. Brands say

   Barley releases energy slowly and steadies blood sugar

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   A 16-dog study replacing corn with 10 to 40% barley found no improvement in glucose after meals. A 15-dog diabetic trial changed peas and processing alongside barley, so its glucose result cannot be credited to barley.^3,10

3. Brands say

   Barley beta-glucan keeps stools firm

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   In a 30-dog comparison, food containing 25% barley left stool consistency unchanged against rice. Dogs eating another extruded diet with more than 50% barley had looser stools. Barley's fiber does not promise firmer stools.^1,2,6

4. Critics say

   Barley is just cheap filler

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   The starch in 6 tested extruded flour diets was more than 99% digested. Barley also contains fiber. It is an economical grain, but its starch supplies energy rather than merely adding weight to a recipe.^1,5,6

5. Owners say

   Barley gluten harms all dogs

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   Barley contains gluten. Affected Irish setters improved when gluten was removed and relapsed after a gluten challenge. That study documents a condition in susceptible dogs, not harm to every dog eating barley.^4,7