From Seed to Feed

Tuesday, September 24, 2024

Managing Your Corn Silage

By Paul Hermans

Imagine waking up and making one meal that you would eat for the next 365 days! You would want to make sure you get it right from the start.

As dairy producers, growing corn silage and harvesting it properly is one of the most important priorities on the farm.

In this article, I will explore tips from seed to feed to help maximize corn silage tonnage and nutritional value.

Hybrid selection

One of the most critical choices dairy producers will make is hybrid selection.

A lot of factors need to be considered, not only from an agronomic standpoint but also from a nutrition standpoint. There are lots of thoughts surrounding hybrid selection. Producers ask me: Do I pick one of the many distinct types of silage specific to brown mid-rid (BMR), or do I select a dual-purpose grain corn?

Using the University of Wisconsin suggestions on hybrid selection, the first place we would start is with our agronomic and technology traits. We want to make sure the corn has all the tools it needs to stay healthy through the year. Grain yield and whole plant dry matter yield work in tandem – traits that are highly correlated because of the importance of grain yield in overall final silage yield. Yield is highly influenced by genetics, so where possible, use local data to assess the performance of the various hybrid genetics. Other considerations include standability, especially if there is the potential for taking some of the acreage for high moisture or grain corn. Relative maturity is vital to ensure the crop has a chance to succeed, and finally, fibre digestibility is a quality component.

On that extensive list of selection criteria, you will notice that fibre digestibility is last. This is a component of silage that is controlled by growing environment and is not something that should be used as a differentiator between non-BMR hybrids. In 2024 so far, we have had ample rain and growth. If this weather trend continues through tassel time, expect lower than average digestible corn.

If fibre digestibility is top of mind, BMR is the way to go.

“Today’s brown mid-rib corn hybrids are very different than what most folks are used to,” says Bill Mahanna, global nutritional sciences manager with Corteva Agriscience.

“We have seen huge gains in the yield of these hybrids, bringing them almost on par with their non-BMR counterparts.”

Today’s BMR corn hybrids also have made advancements in plant health and starch yield, while maintaining the fibre digestibility advantage they have become known for.

The other important hybrid selection criteria to consider is relative maturity. Think of the end in mind when it comes to picking maturities ranges. Ask yourself, “On average, how many days does it take to put up corn silage?” If you harvest corn silage in two to four days, keeping to one maturity range of corn silage is recommended. If harvest takes a week or more and the harvest is all stored in one structure (bunker/upright silo, etc.), then spreading harvest maturities may be advisable to avoid rapid dry down in the field and avoiding dry silage at peak harvest times.

The rule of thumb is selecting a hybrid that is five to 10 days longer than what is adapted for grain corn, or about 250 CHUs longer. Whether it is five days or 10 days depends on your risk tolerance for frost and what other activities you have planned in the fall. If you have manure to get out or a cover crop to plant, plan to use a shorter hybrid.

Crop management

Overall production tips that are common for grain corn production are the same for silage production. I always tell silage producers I work with, “Plant your silage corn first and plant it on the best land you have available.” Making top-notch silage is key, as your cows need consistent high-quality corn silage with nutritional qualities that help achieve high milk production. Tonnage comes into play from a return-on-investment standpoint as well.

Like grain corn, corn silage population strategies should be based on yield environments and water holding capacity at a field and sub-field level. For dual purpose or specific silage (non-BMR), plant 2,000 to 4,000 more plants per acre than grain corn. Working with your agronomy team, determine the hybrid’s response to different populations, and your yield environment to find the sweet spot for population. On the other side, BMR hybrids are not pushed to the same extent for population.

“BMR is water-sensitive, so we don’t want to inadvertently put the crop in a stress situation by increasing our population,” notes Mahanna.

Now that the crop is up and going, what do we look for next?

Fungicides in corn silage are becoming more normal across livestock-producing areas for their benefit to both silage yield and quality, as well as their importance in protecting the plant against disease that could produce toxins. Data from Ohio State University has demonstrated that proper fungicide application has reduced the deoxynivalenol (DON) toxin load in a plant by 50 per cent. This aids in nutritional value as well as overall tonnage.

Harvest tips

After putting in all the work to grow the crop, it will not mean anything if we do not take the time to get harvest right.

Harvest timing is the first crucial step. In years past, we focused on whole plant moisture to determine the right time for our storage structures. More recently, improved genetics has helped maintain late-season plant health, making the plant’s dry-down more predictable. With this shift, we can start to consider milk line progress in conjunction with overall plant moisture.

In Ontario, we can expect to see a moisture decrease of about 0.5% per day, as the Ontario Ministry of Agriculture, Food and Agribusiness states. On hot days or in dry years, this number is much more likely to be closer to one per cent. Since the conversion of kernel milk to starch is the largest driver of the drop in plant moisture, we can safely assume that we are gaining about 0.5% to one per cent of starch.

If we know the weather, the harvester’s schedule, and have confidence in our ability to store our corn silage crop, we can wait two to three days to harvest our silage and capture 1.5% to three per cent more starch.

This good energy source for our herd will have a direct impact on our feed costs by reducing our need to bring in energy from elsewhere, whether that is buying some in or allowing us to sell more of our on-farm corn.

An important thing to watch when we harvest our silage is our kernel processing success. Our increased starch content will not matter if we do not “unlock it” for the rumen to access. Previous standards would have said that “knicking” the kernel was sufficient to allow the cow to capture that starch, but more modern research from institutions like the University of Wisconsin would state that we need to be much more aggressive.

When viewing a feed test, a score of 70 per cent on our Corn Silage Processing Score (CSPS) metric is the new target. A quick in-field test to gauge our work on kernel processing is to take a one-litre harvested silage sample and examine the number of whole or half kernels present. If the number is greater than four, we have room for improvement. Ensuring we have a sufficient roller differential, sharp knives and an acceptable product intake rate through the processor are all things we can quickly check and tweak to improve our kernel processing.

Finally, adding a silage inoculant helps reduce fermentation losses while improving nutritional qualities.

Make sure you do your homework on silage inoculants. Not all inoculants are created equal, and specific inoculants will assist with unique needs in your farm operation (for example, reducing bunk heating at feed out while minimizing losses at the bunker face).

In summary, silage hybrid selection and management are key to producing top-notch feed for your dairy operation. By focusing on hybrid selection tailored to local conditions, precise crop management strategies, optimal harvest timing, and quality preservation techniques, producers can enhance both yield and nutritional value, supporting healthier and more productive dairy herds.

Here is hoping you have a safe and productive silage harvest season. BF