Buying corn silage to feed beef cows in winter

COLUMBIA, Mo. — Moisture and fall forage growth have been disappointing in 2024. The bumper crop of corn this year has prompted many cattle farmers to consider feeding their cows corn silage.

“We had an outstanding growing season, and hay supplies are plentiful,” said University of Missouri Extension state beef nutritionist Eric Bailey in a press release. “But I have received numerous inquiries from cattlemen interested in using corn silage as a winter feed option for beef cows.”

There are special considerations for those who do not grow corn and have not previously fed corn silage but want to evaluate it as a winter feeding option, said Bailey.

What should the price of corn silage feed be?

Historically, corn silage is priced at 10 to 12 times the price of a bushel of corn delivered and packed in a bag, bunker or pit. With corn currently hovering around $4 per bushel, it is reasonable to expect corn silage to be priced in the range of $45 to $50 per ton, Bailey said. Corn silage is a wet feed; when stored correctly, it typically consists of two parts moisture to one part dry feed. Therefore, on a per ton of dry feed basis, a reasonable price is between $136 and $151 per ton. This may seem expensive compared to grass hay, which is currently selling for $40 to $60 per round bale. However, there is a significant difference in the pounds of total digestible nutrients obtained in corn silage compared to grass hay.

“Let’s assume that fescue hay tests at 55% total digestible nutrients (TDN), which is optimistic if you harvested round bales in July and are just now picking them up from the field,” Bailey said. Every ton of hay testing at 55% TDN will contain 968 pounds of TDN (assuming 12% moisture, which explains why the total is not 1,100 pounds of TDN). If a bale is assumed to weigh 1,000 pounds and is priced at $50 per bale, then the cost of each pound of TDN from the hay is $0.1033.

Corn silage contains 70% TDN. If a ton of dry corn silage provides 1,400 pounds of TDN and the purchase price is $143.50 per ton, then the cost of TDN from corn silage is $0.1025 per pound. Small fluctuations in price on an as-fed or wet basis can significantly affect the cost per pound of TDN for corn silage. For instance, corn silage priced at $60 per ton equates to $181.82 per ton of dry matter, or $0.1299 per pound of TDN. A lactating beef cow needs about 18 pounds of TDN per day during peak lactation, resulting in an increased cost of $0.4788 per cow per day with a price increase of roughly $12.50 per ton (as fed).

Consider the shelf life of corn silage

The purpose of packing corn silage is to remove oxygen from the feed, facilitating anaerobic fermentation. When proper fermentation occurs, organic acids are produced that inhibit mold and microbial growth, thereby preventing spoilage. However, when the feed is exposed to oxygen again, mold and microbial growth resume.

“If I were purchasing corn silage from a neighbor, I would prefer to take delivery at least once a week,” said Bailey. It is unwise to create a secondary pile on your farm that is replenished monthly or less frequently. The feed will degrade, resulting in a loss of nutritional value. In the worst-case scenario, cows may refuse to eat it.

Corn silage contains both forage and grain. It does not need to be fed in conjunction with dry hay due to the presence of leaves, husks, stalks and cobs in the silage. However, some farmers mix hay with corn silage to extend their feed supplies or to reduce the energy density of the ration, allowing for a less precise feeding approach (free choice).

“In my opinion, this practice is wasteful, and I generally do not recommend it,” Bailey said. If anything, corn silage is slightly deficient in crude protein. A well-balanced ration that can be fed to cows, calves, backgrounders or other livestock consists of nine parts corn silage and one part dried distillers grains on an as-fed basis.

“I have observed operations with limited equipment where corn silage is offered free choice to beef cows in old tractor tires. I do not recommend this practice due to the potential for waste and the lack of control over the amount of feed provided,” he said.

It is important to remember that this feed is not significantly cheaper than dry hay and has a shorter shelf life. Additionally, because corn silage is a wet feed, it is necessary to offer much more than 30 pounds per day.

“In fact, it would not surprise me to see a large-framed, fall-calving cow consume upwards of 80 pounds of corn silage per day on an as-fed basis,” Bailey said. “This feed is most effectively utilized in operations where the quantity provided can be measured and administered daily.”

Transportation considerations

“Due to the amount of moisture per ton, I would not want to haul it more than 20 miles. Freight will get pricey otherwise,” Bailey said. “If you operate with minimal equipment, buying dry hay at current prices might be the least unfavorable option if you need to purchase feed on the market this fall and winter.”