Aug. 22, 2016 11:27 AM

Fiber digestibility tests offer insights to maximize the value of high-quality forages.

This item has been supplied by a forage marketer and has not been edited, verified or endorsed by Hay & Forage Grower.

Have you ever switched forages or made minor changes to the ration and had milk production drop? Even minor changes in forage quality can impact production in a big way. Having a handle on forage quality as well as a test to accurately measure forage quality will be key to maintaining milk production, especially with new high-quality alfalfa varieties, like HarvXtra® alfalfa, coming to market.

“If forage quality is unusually high or low, not average, NIR analysis can be less accurate,” says David Weakley, Ph.D., director of dairy forage research for Calibrate® Technologies. “If we look at the bar chart in Table 1, the vertical bars represent a typical frequency distribution of a lab’s alfalfa hay quality test results. The light bars at the ends of the ‘bell curve’ represent where alfalfa fiber quality is either unusually high or low. The analysis accuracy of these extremes is financially critical.”

As new varieties of high-quality alfalfa enter the marketplace, it’s important to measure and understand digestibility. High-quality forages are more digestible, and digestibility can have a big impact on rumen function.

For example, if you decide to change alfalfa varieties to a genetically enhanced variety with a 10-15 percent decreased lignin content, the digestibility of the fiber, and the resulting effect on rumen fill, will change. Research shows this reduction in lignin can result in a 10-15 percent increase in digestibility, proving minor changes in lignin can have a major impact on digestibility.[1] <#_ftn1> The use of a fiber digestibility test will ensure accurate utilization of forages in the ration and help sustain milk production.

To minimize potential variability in results and maximize forage performance, tests for neutral detergent fiber (NDF) and neutral detergent fiber digestibility (NDFd) should be conducted, in conjunction with analysis for other essential nutrients. By providing more accurate insights into the quality of forages being fed, a fiber digestibility test can also help optimize the cows’ diet for higher intake and milk production or higher feed efficiency.

A review by Oba and Allen illustrated the impact fiber digestibility can have on milk production. The research showed a one-unit increase in the in-vitro digestibility of neutral detergent fiber (NDF) resulted in a 0.37-pound per day increase in dry matter intake and a 0.55-pound per day increase in 4 percent fat corrected milk yield per cow.[2] <#_ftn2>

Fiber digestibility tests give you an edge by providing precise insights where it matters most – in the rumen. These insights allow optimization of feed use in the ration to help achieve a higher standard of nutritional performance with benefits like an increase in forage utilization, higher animal performance and greater profit potential.

Want to make sure you’re getting your money’s worth with your forages? Call 800-635-5701, email: or go to: to receive more information on forage quality tests.

Calibrate® Technologies provides the dairy industry’s first rapid starch and fiber test with an online nutritional calculator to help provide ration recommendations to nutritionists and producers on rumen digestibility of forages and feedstuffs. For additional information, visit <> or call 800-635-5701.

Producers can benefit from Calibrate® Technologies patented processes (see, e.g., US Patent 8,940,322). Using Calibrate® Technologies’ ruminal starch and NDF digestibility data, dietary levels of rumen digested starch (RDS) and rumen undigested NDF (RUNDF) can be calculated. Further employing Calibrate® Technologies’ patented processes and knowhow, dietary RDS and RUNDF levels can be manipulated to affect feed intake, digestibility and feed efficiency.