A spreadsheet that helps scientists, nutritionists and producers predict corn silage hybrid performance has been retooled.
Milk2006 is more closely related to animal performance than previous versions, which were introduced in 1990, 1995 and 2000, says Randy Shaver, a University of Wisconsin dairy nutritionist who was instrumental in its development.
“The equations are more in line with the 2001 National Research Council (NRC) Nutrient Requirements for Dairy Cattle,” says Shaver. “It does a better job of accounting for the effects of fiber digestibility and how they're apportioned between intake potential and the energy density of silage.
“I analyzed 10 studies published in the Journal of Dairy Science that had dairy cattle intake and production data and compared them to the prediction of milk per ton using either Milk2000 or Milk2006. Milk2006 does a better job relative to the animal data that's available.”
The spreadsheet calculates TDN and NEL values that can be used by nutritionists in ration formulation and diagnostics. It also calculates milk per ton (quality) and milk per acre (yield x quality) values that producers can use to select the silage hybrids best suited for their locations and needs.
The best example of the model's usefulness, he says, is the University of Wisconsin corn silage hybrid performance trials. They're conducted by Joe Lauer, extension corn agronomist, at 10 locations across the state.
“Every fall, Joe publishes a booklet that compares the nutrient composition and yield of over 500 hybrids,” says Shaver. “This year's data will be derived in part from Milk2006.”
Many universities, extension offices, forage councils and large-acreage producers who run test plots also use the spreadsheet to compare hybrids, he adds. And it's used by seed corn companies in their breeding and hybrid evaluation programs.
“That's more of a behind-the-scenes utility of Milk2006, but ultimately, it impacts producers,” says Shaver.
The spreadsheet can be downloaded free at www.wisc.edu/dysci/. Click on Extension, then Nutrition and finally, Spreadsheets. At Spreadsheets, scroll down to Milk2006.
Will there be a Milk2010 or 2011?
“If there's an opportunity to make it better, we'll do that,” says Shaver. “One of the areas that would be open for improvement in a later revision would be to get a better handle on starch digestibility than what we currently are doing.”
More Mileage From Silage
Joe Lauer will put Milk2006 through its paces this year as he uses the spreadsheet to analyze the 500-plus corn hybrids grown in University of Wisconsin silage hybrid performance trials.
“It's a step forward,” says Lauer, extension corn agronomist, of the new software program. “In the past, I think we've overestimated how much milk you could get out of a ton of silage, and now I think we're closer.”
Trial results will be posted in November on his Web site, corn.agronomy.wisc.edu/ (click on Corn Hybrid Trials).
Whether in Wisconsin or other states, producers should carefully study hybrid information provided by universities and seed companies, Lauer says.
“Hybrid selection is a very important management decision in silage production,” he adds. Lauer recommends picking silage hybrids for high forage yield and stover digestibility.
Look for hybrids with the best combination of yield and quality. Using university and seed company data, narrow choices to 10 or so high-yielding, highly digestible hybrids with the maturity and agronomic traits you need.
“If you select a hybrid from that list of 10 or so, you're going to be working with a good one,” he says.
In the past, yield was the most important silage hybrid trait, but that's not necessarily the case anymore.
“It depends on your perspective,” says Lauer. “For producers growing corn silage for their own farms, yield is probably the top consideration. But, when you're buying corn by the truckload for your high-producing dairy cattle, quality's more important.”
As he analyzes data from this year's crop of hybrids, he'll be closely watching a few new developments.
“There's a lot of interest in the stacked traits and how they will affect the yield and quality of corn silage. A lot of biotechnology is arriving at the farmer's gate. He has access to a lot of hybrids that he hasn't in the past. This will continue to build.”
Brown midrib (BMR) hybrids may warrant another look, too, he says.
“Five years ago, there was quite a yield hit with BMR hybrids. But from what I understand, some of those hybrids are yielding better and that gap is starting to narrow.”