Corn silage may require extra fermentation time this year

FORT ATKINSON, Wis. — Corn silage harvested this year has a unique set of characteristics.

“I can’t recall a crop like the one we are likely going to be seeing, if not already feeding,” said John Goeser, director of nutritional research and innovation at Rock River Laboratory.

Looking at a feed analysis, Goeser said, the rumen starch digestibility is the unique characteristic of the 2021 crop.

“That may give us some fits because it may take the crop three to four months longer for it to feed to its full potential,” he explained during the Dairy Livestream event hosted by Hoard’s Dairyman.

“We had dry growing conditions coupled with adequate to more than adequate heat units,” he said. “Heat units and moisture are influential factors relative to the outcome of feed quality and yield.”

Many cornfields experienced drought stress early in the year.

“The plant is imprinted around V5 to V7, so there was pretty good fiber quality,” Goeser said. “We were getting worried as we got into tasseling, but the water turned on and we got adequate moisture through pollination and grain fill, so we ended up with strong grain yields.”

As a result, the test weights for the corn are up, the fiber quality is average to above average and the yields are decent.

“We’re seeing less in rumen starch digestibility, so it doesn’t look like we’ll capture the full potential of the silage compared to prior years,” Goeser said.

Therefore, it is important for dairymen to know the feed inventory on their farm to determine if adjustments need to be made in the feeding program, said Mike Hutjens, professor emeritus at the University of Illinois.

“I hope you have inventory to allow this year’s crop to ferment,” Hutjens said.

“Normally, forage NDF is at 20% to 21%, so when you get down to 15% forage NDF, you have to increase the NDF in the ration,” he said. “You may use another forage resource or look at byproduct feeds to get that job done.”

Hutjens recommends dropping the starch content to 22%.

“That’s because you’re putting more pressure on the rumen fermentation program,” he said.

For mycotoxins, Goeser said, it looks like the levels for the crop this year are moderate to down a little.

“We didn’t see much mycotoxins until tar spot started to move in,” Goeser said.

“Mycotoxins are concentrated in distillers grains, so eyes wide open if you’re buying distillers from the Dakotas,” Hutjens said.

“Hopefully all of you have been processing your corn harder down to 1 millimeter,” he said. “The kernel processing score should be in excess of the 70s.”

“Feed issues tend to show up in milk per cow first,” said Chris Wolf, agricultural economist at Cornell University.

“Nationally milk production per cow was down year over year in October by 6 pounds,” Wolf said. “In states with drought, milk per cow was down 24 to 35 pounds in October compared to the previous year, so we are seeing some feed issues show up.”

Cover crops can help dairymen increase feed supplies.

“Cover crops can be an extremely good crop that really fit nicely if you catch it right,” Hutjens said. “For those who have cover crops in now, they will be the first crop off next spring which can allow you to stretch corn silage inventories.”

“Since many of the cover crops are grasses, they are responsive to maturity in terms of quality,” Goeser said. “If you harvest them before they head out, it can be exceptional dairy quality feed to stretch inventories.”

“Having more feed inventory is a risk management issue as long as we’re not worrying about quality going down from being too old or not stored right,” Wolf said. “There is an opportunity cost for having it sitting there, it depends on what else you could be doing with your time to put it up and the storage space — it’s a tradeoff between risk management and opportunity cost.”

Some dairies, Goeser said, are storing 12 months of feed inventory.

“This year we have a harder grain so dairies that have more inventory might be in a better position to store the silage longer.”

Milk prices for 2022 are bullish, Wolf said.

“U.S. milk production is down year over year and both New Zealand and European Union milk production is down, too,” he said. “Some of that is related to weather and some is related to new environmental rules.”

Class III contracts for 2022 are trading between $19 and $20 per hundredweight, Wolf said.

“The Class IV contracts are in the same neighborhood which reflects the tighter butterfat supplies,” he said. “We forecast 2022 should be a pretty decent farm milk price year.”