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 economy 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:
· NDF digestibility over a period of time (NDFd)
· Rate of digestibility (kdNDF)
· 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.”
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. 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.
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.
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.
“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.”
A summary of Hall’s recent presentation to dairy consultants can be viewed on Lallemand Animal Nutrition’s YouTube channel.