Fiber Content of Barley

Asked April 10, 2016, 2:23 PM EDT

I'm confused. On your Feeding Barley to Poultry page you state in the narrative that barley contains about 22% fiber, but in the table immediately below (from the Ingredient Analysis Table 2011) the grid shows crude fiber of only 5%. Please reconcile the apparent difference -- it's very important to me because grain barley is a large part of the diet of my poultry and I need to ensure that the animals are receiving proper nutrition. Thanks!

Hernando County Florida

3 Responses

Fiber levels are our attempt at measuring digestibility. Fiber content can be expressed in different ways. It also can depend on the class of livestock. Ruminants like cattle can digest a large portion of the fiber. Here is a excerpt from Understanding Feed Analysis for beef from Nebraska. Crude fiber was the attempt at measure the non digestible portion of feed ingredients.

Crude Fiber (CF):
Crude fiber is a traditional measure of fiber content in feeds. Neutral detergent fiber (NDF) and acid detergent fiber (ADF) are more useful measures of feeding value, and should be used to evaluate forages and formulate rations.

Neutral Detergent Fiber (NDF): Structural components of the plant, specifically cell wall. NDF is a predictor of voluntary intake because it provides bulk or fill. In general, low NDF values are desired because NDF increases as forages mature.

Acid Detergent Fiber (ADF): The least digestible plant components, including cellulose and lignin. ADF values are inversely related to digestibility, so forages with low ADF concentrations are usually higher in energy.

Poultry are non-ruminants, so they have a larger portion of the fiber that is non digestible. Total fiber is all of the cell wall components. Here is the NRC Feed Composition Tables that show the feed values of all feeds for individual classes of livestock. Lines 67 and 68 are barley grain. It runs across pages 10 and 11.

So reading the table that you reference via the link (http://www.nap.edu/read/1713/chapter/8#11), NDF would be approximately equal to the column headed CELL WALLS %, which in turn is approximately equal to the columns headed CELLULOSE % plus HEMICELLULOSE % (even if the amount is not shown in the table) plus LIGNIN %, and where ADF is equal to CELLULOSE % plus LIGNIN % ?? Sorry for the run-on sentence..........

Approximately, yes. Although remember that these are average values. Field conditions, variety, and harvest and storage losses can affect the relative values.