Both Barmore and Kurtz plan to do more extensive monitoring of ensiled Shredlage throughout its feeding life this year. In theory, a higher level of processing should change the timeframe of fermentation, potentially making it possible to feed higher-quality silage sooner after harvest. Kurtz collected dozens of samples “off the spout” as Shredlage was made on various dairies this past fall, and he will compare those results to samples taken from now-packed Shredlage, as well as during feed-out from bunker faces. Barmore plans to take composite samples from feeding faces throughout the feeding period — as frequently as once a week — to measure changes in feed value throughout the “lifetime” of this year’s Shredlage crop.
Initial research shows promise
Because Shredlage is a fairly new innovation, formal research to evaluate its merits is just beginning. One of the first Shredlage studies was conducted by extension dairy nutritionist Randy Shaver and his colleagues at the University of Wisconsin.
In that trial, nine acres of corn were chopped as Shredlage at a particle length of 30 mm, compared to conventional corn silage chopped at 19 mm with a kernel processor. Both crops were ensiled in plastic silage bags. The 112 cows in the trial were divided into two feeding groups and fed either the conventional corn silage or Shredlage.
The results showed that:
• Corn silage processing score, defined as percent of starch in silage particles <4.75 mm, for conventional corn silage was 60 percent, compared to 75 percent for Shredlage.
• Feed intake for Shredlage was higher by 1.5 pounds per day.
• Milk production (3.5 percent fat-corrected milk [FCM]) was 3.0 to 4.5 pounds per day higher for the Shredlage group after several weeks on the trial.
• FCM efficiency averaged 1.78 for both groups.
• Total tract NDF digestibility was 4 percent higher for Shredlage.
• Total tract starch digestibility was 1.9 percent higher for Shredlage.
Will it pack, will it pay?
In his discussions with nutritionists and dairymen regarding Shredlage, Kurtz says two major concerns are: (1) Will the large particle size of Shredlage interfere with excellent packing and fermentation in the bunker or bag? and (2) Will the additional cost for processing Shredlage (currently a premium of about $25/hour or $0.75-$2/ton) be offset by ration adjustments and/or production gains?
Both of these are legitimate concerns, he says.
Today, he has a concrete answer for one of the two: Any differences in silage quality are due to packing techniques and procedures, not in the way the silage was processed.