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Investing in quality corn silage can pay off

Chad Howlett Published on 24 July 2012
Packing a bunker

As I put this article together in mid-June, much of the central and eastern Corn Belt is in need of precipitation.

While the future of this corn crop is still very much in doubt, it goes without saying that we want to try and make the best feed we can for our cattle and generate the most return per harvested acre. If that means making lemonade out of lemons, then so be it.

When it comes to putting up corn silage, I’ve seen and heard a lot of reasons for not putting up the best possible feedstuffs for the feedlot, backgrounding operation or cowherd.

Every producer probably has this goal in mind – but everyone takes a different approach toward producing good corn silage.

Under most normal conditions, dry matter losses of corn silage during storage will be between 10 to 15 percent.

These losses are either from the result of poor fermentation (30 to 40 percent) or aerobic instability (60 to 70 percent). That said, you can use and implement different practices to make sure these numbers don’t increase.

Cover the resource

One of the more basic approaches is to cover your silage pile. In my travels, I still see silage piles that aren’t covered.

Early dry matter loss studies from UC – Davis in the late 1960s used Dacron bags placed at various levels in bunker silos. The studies indicated dry matter losses ranging from 10.3 to 55.6 percent in the top 4 feet of silage in uncovered bunkers.

Take a silage pile that is 200 feet long and 150 feet wide with an average depth of 25 feet. That pile contains 750,000 cubic feet of silage (200 X 150 X 25 = 750,000).

If average density of 40 pounds per cubic foot of as-fed silage is achieved, that means you have 30 million pounds of feed in the pile (750,000 X 40 = 30,000,000) or 15,000 tons.

If we just look at the top 4 feet of that silage, we can calculate 2,400 tons of feed in that top layer. If dry matter losses approach 55 percent, as was found in those early research trials, the total dry matter loss in the top layer is 1,320 tons of as-fed silage.

Even at $50 a ton, that’s a loss of $66,000. Whether beef prices are good or bad, that’s a loss that can’t be ignored.

Boosting the return

Another step that can be taken is to inoculate your silage. Lab-scale silo savings are typically 2 to 3 percent of the dry matter.

This is primarily achieved through a quicker, more efficient fermentation. In farm-scale silos or bunkers, with less perfect conditions, the dry matter savings could potentially be greater.

If we take our 15,000-ton bunker and can reduce our loss by 3 percent (450 ton; $50 per ton), that yields a savings of $22,500 of feed. This doesn’t even include the extra feed you would need to purchase to replace your loss.

Harvest timing and moisture can be critical to your returns as well. Data recently generated at the University of Nebraska showed delaying chopping by two weeks can have a negative impact on harvested nutrients per acre.

While the silage had more grain in it, and resulted in a greater TDN value, the dry matter yield per acre was nearly two tons less, primarily from the solubles portion of the corn plant, which contains many sugars.

This resulted in a 15 percent reduction in harvested TDN per acre and a reduction of nearly $310 per acre when you value corn at $5 per bushel.

While not reported, I would speculate the losses during storage would have been greater for the delayed-harvested silage as well.

When forage moisture is too low, air can remain entrapped within the silage mass. This encourages growth of spoilage organisms and causes excessive heating, as well as loss of water-soluble carbohydrates and dry matter.

Measure of moisture

To further delve into the effects moisture can have on corn-based forages, we’ve collected samples in the field to examine the effect earlage moisture has on fecal starch.

Diets containing earlage moisture levels of greater than 30 percent yielded an average fecal starch concentration of 6.1 percent, while diets with earlage moisture levels 21 percent or drier yielded fecal starch concentrations of 19.4 percent.

In other words, the lower moisture level led to more starch passing through the animal instead of being metabolized for maintenance or growth.

The moistures of the drier samples were not targeted at that level but conditions allowed for the crop to become drier than what producers anticipated. Attention to detail needs to be paramount when the chopping season approaches.

With the onset of high corn prices over the past few years, producers may be looking to increase the use and quantity of silage in feedlot diets.

We’ve seen a lot of interest in using corn residues, like corn stalks over the past several years, but the “residue” portion in corn silage is of much higher quality as it retains the solubles that are lost in dry corn residue.

Additionally, some evidence shows a synergistic effect may exist between distillers grain and the feeding of corn silage.

While inclusion of higher levels of corn silage will yield a reduction in gain and feed conversion, that reduction may not be as large as you might think.

Data recently generated out of the University of Nebraska suggest that higher inclusion of corn silage may yield a more profitable return.

They fed diets containing 40 percent modified distillers grains and 15, 30, 45 or 55 percent corn silage with the increasing silage level replacing corn.

Their data suggested an advantage of about $27 per head when feeding a diet including 45 percent silage (valued at 8.5 X corn price of $5 per bushel, or $42.50 per ton) compared to silage included at 15 percent even though gain was reduced by 0.28 pounds per day and feed conversion reduced by 5 percent.

When corn was valued at $6.50 per bushel and silage price was adjusted accordingly, the return climbed to about $33 per head.

Some other factors that can impact quality and return, like hybrid selection and planting density, are already determined.

However, as you get ready to make your chopping plans, if it’s lemons you’re dealt, try to make as good of lemonade as you can this year.

Maybe even add a little extra sugar. Work with your consultant to put the right plan in place for your operation.  end_mark

PHOTO

Proper silage coverage can bring major feed savings. Photo courtesy of Progressive Cattleman staff.

chad howlett

Chad Howlett

Beef Technical Manager
Vita Plus Corporation

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