Corn can be an attractive option for feeding cattle, but there are a lot of specifics to consider when you choose to grow it.
“Corn just tastes good and cows love it. It’s more palatable than barley, and it has a better dry matter intake,” Greg Paranych, agriculture field specialist with the Grey Wooded Forage Association, said during a webinar last month on growing corn for grazing or silage.
Paranych outlined further comparisons between corn and barley. Corn costs more to grow per acre than barley, and requires more heat units, but it is more water efficient and drought tolerant. Barley grows better in cooler temperatures.
Whether you’re growing either barley or corn, you need a good harvest plan, and that’s critical if you want to get high-quality corn silage.
The growing season and available heat units for plant development will affect both corn’s maturity and starch target. The barley target is at the soft-dough stage. That’s where you can get a higher fibre content in barley than in corn. Barley harvest is earlier in the season than corn.
“Some people are starting to harvest barley at the head-emergent stage for a higher feed quality, and lower fibre,” said Paranych. “Barley also has higher moisture, so that has to be managed as well.”
And if you want to get serious about growing corn, you’re going to need to buy a corner planter or harvester.
“But if you’re starting out, you want to rely on a custom planter or chopper service to do that specialty work for you,” he said.
Barley and corn have different feed values. In corn, starch is 20 per cent versus barley’s 12 per cent. Corn has about eight per cent protein, while barley has about 11 to 12 per cent protein. And corn has about 45 per cent non-digestible fibre, while barley has about 55 per cent.
Hybrid corn selection is critical and it’s important to know the end use for your corn, said Sara Meidlinger, market development specialist for Pride Seeds.
“Are you going to silage the corn or are you going to graze the corn? That could change what you’re looking for,” she said.
She noted that the amount of time it takes for corn to mature is dependent on corn heat units (CHUs) and those are limited in the counties covered by the Grey Wooded Forage Association (which are Lacombe, Red Deer, Ponoka, Clearwater, Mountain View and Wetaskiwin).
“The average corn heat units for the area are about 1750 to 1800,” she said.
For silage corn, the corn has to be at approximately 62 to 68 per cent whole plant moisture when the chopper starts chopping the field. When selecting a hybrid corn variety for silage, you can select one with a CHU hybrid rating approximately 150 more CHUs than the corn heat unit maturity rating for your area, she said.
“Remember, we don’t want plants to reach physiological maturity because silage palatability and digestibility are greatly reduced,” said Meidlinger.
When grazing, cows will go for the cobs first, then the rest of the plant. Grazing corn needs to be less mature than when it is cut for silage, so it doesn’t have a negative effect on the rumen.
Meidlinger recommended growers consider growing two to three different hybrids at different maturity ranges in order to manage risk. It’s good to talk to neighbours and look at seed company’s plot trials to find out how hybrids perform in different areas, she added.
The goal when planting is to strive for even emergence and consistency. Using a corn planter helps with both consistency and depth (seed should be planted about 1-1/2 to two inches deep).
“If we can get it into moisture right off the bat, you will really set the seedling up for success,” she said.
Ideally, soil temperature at the planting depth should be about 10 C.
“If we can have a 48-hour warming trend, that is even better for the seedling to get started off at a good note,” said Meidlinger.
Corn is grown on a seeds-per-acre basis (rather than a pounds-per-acre basis) and Meidlinger recommends a target of about 32,000 seeds per acre. The seedbed needs to be nice and firm. The area should be free of excess tillage that can lead to crusting and compaction, which can affect root development and emergence.
Planter speed should be targeted at about 4.5 to five miles per hour at maximum. Maintaining speed allows for good spacing, and even uniformity.
“If the speed increases, the space between the rows isn’t as good, and the depth uniformity decreases,” she said.
With optimal emergence, the corn seedlings will emerge 10 to 14 days after planting.
“Even emergence is really critical,” she said. “Corn is a poor competitor with weeds, and with itself. So if we have plants popping up at different times, that will affect the yield. Yield loss from uneven emergence can range from five to 10 per cent. So hopefully we have all of our corn plants emerging within 48 hours of each other.”
Soil testing is very important when growing corn as it’s key to get the macronutrients correct, she added.