The information below has been supplied by dairy marketers and other industry organizations. It has not been edited, verified or endorsed by Hoard’s Dairyman.

Nutritionists and dairy producers need a lot of information about forage inputs to formulate a workable ration. Among the most critical is neutral detergent fiber (NDF) analysis. A solid understanding of NDF allows nutritionists and producers to make an economical ration designed to help cows maximize milk and milk component yield while optimizing rumen function and health.

“NDF is really the functional fiber in the forages fed to dairy cows,” notes Anthony Hall, MSc MSB, PAS, Technical Services – Ruminant, with Lallemand Animal Nutrition. “NDF is the basis of the farm-grown forages that lead to the greatest economy1 and highest milk production in our dairy herds.”

NDF gives dairy producers a measure of how digestible the forages are on the farm, but it’s actually composed of three separate measurements:

1) NDF digestibility over a period of time (NDFd)

2) Rate of digestibility (kdNDF)

3) Ballast or “fill” of NDF (undigestible NDF, uNDF, or iNDF)

“Taken together, this tells us how digestible the forages are on the farm, how quickly the digestion takes place and what the limitations to digestion might be,” Hall says. “There are quick and economical laboratory analyses available to help producers get this data.”2,3

With this information, producers and nutritionists can tweak both lactating and dry cow rations every two or three weeks on some large farms. Often these are small adjustments. However, sometimes weather events don’t allow producers to harvest forages at the optimal time, which compromises NDF digestibility.

“In these cases, it may mean we need to feed more grain, but it could be there are other solutions,” Hall says. “More and more producers are turning to probiotic feed additives to improve NDF digestibility in challenging forages or in the whole ration.”

In these cases, producers may consider including an active dry yeast (ADY) probiotic. One ADY probiotic, Levucell® SC — which includes the strain Saccharomyces cerevisiae CNCM I-1077 — can help improve NDF digestibility in rations.4 It also has been proven to help producers manage Sub Acute Ruminal Acidosis (SARA). Even when fed with good-quality feedstuffs, cows supplemented with S. cerevisiae CNCM I-1077 can experience increased milk yield.5

In a meta-analysis of 14 research trials, cows supplemented with S. cerevisiae CNCM I-1077 showed an increase of 2.1 lbs. of 3.5% fat-corrected milk (FCM) and were more efficient than control cows.6

Another way to manage NDF digestibility in forages is by applying a silage inoculant at ensiling. This helps manage the digestibility of the forage before it’s inside the bunk. Inoculants also can help prevent production drops by maintaining feed quality and improving stability of the silage.

For instance, Lactobacillus buchneri 40788, applied at a minimum of 400,000 colony-forming units (CFU) per gram of silage or 600,000 CFU per gram of high-moisture corn (HMC), is the only inoculant bacteria strain reviewed by the FDA for improved aerobic stability.7

“We’re understanding NDF in a lot more detail,” Hall says. “Now, we can both complement and supplement our forage base to make sure we’re optimizing rumen function and maximizing milk yield.”

Listen to Anthony Hall (click above video)

A summary of Hall’s recent presentation to dairy consultants can be viewed on Lallemand Animal Nutrition’s YouTube channel at:

Lallemand Animal Nutrition is committed to optimizing animal performance and well-being with specific natural microbial product and service solutions. Using sound science, proven results and knowledge, Lallemand Animal Nutrition develops, produces and markets high value yeast and bacteria products ─ including probiotics, silage inoculants and yeast derivatives. Lallemand offers a higher level of expertise, leadership and industry commitment with long-term and profitable solutions to move our partners Forward. Lallemand Animal Nutrition is Specific for your success. For more information, please visit

1 Mertens DR. ND and DMI – Has anything changed? Proceedings of the Cornell Nutrition Conference for Manufacturers. Oct. 19-21, 2010. East Syracuse, New York.
2 Ward RT. Opportunities and limitations in the use of NDF fiber digestibility values. Cumberland Valley Analytical Services, Inc. Penn State University Dairy Cattle Nutrition Workshop. Nov. 9-10, 2005. Grantville, Pa.
3 Allen M. Forage fiber digestibility in relation to dairy cow performance. Proceedings of the Intermountain Nutrition Conference. 2006.
4 Guedes CM. Effect of S. cerevisiae yeast on ruminal fermentation and fiber degradation of maize silage in cows. Animal Feed Science and Technology. 2008(145):27-40.
5 Bitencourt LL, et al. Diet digestibility and performance of dairy cows supplemented with live yeast. Sci Agri. 2011;68(3):301-307.
6 de Ondarza MB, Sniffen CJ, Dussert L, Chevaux E, Sullivan J, Walker N. Case study: Multiple-study analysis of the effect of live yeast on milk yield, milk component content and yield, and feed efficiency. The Professional Animal Scientist. 2010(26):661-666.
7 United States Food and Drug Administration allowed a functionality claim for Lactobacillus buchneri for improved aerobic stability in ensiled feeds. This claim was based on L. buchneri NCMIB 40788 research dossier submitted by Lallemand Animal Nutrition.