The author is a dairy nutrition consultant with GPS Dairy Consulting LLC and is based in Malone, Wis.
It's corn silage harvest season — a short window of time that affects dairy profitability all year long. What can go wrong? Unfortunately, there are many things that can and do go awry on an annual basis. Some are out of our control while others are not. In my experience, here are five corn silage harvest mistakes that happen too often and have a profound negative impact on the crop we’ll feed over the next year.
1. Poor communication: After the harvest season, it’s easy to assess that something went wrong. The fingers start pointing. The chopper was set according to the manual, but the corn silage was chopped too fine. The reality is that most harvest issues are people issues and not weather or equipment related. The solution, of course, starts with pizza.
Get your forage team together a couple weeks or months before harvest. This group should include the people doing the chopping along with your agronomist, nutritionist, operations manager, and the owner. Decide who will monitor chop length and kernel processing. Make sure everyone shares their phone number and maybe start a WhatsApp group.
Do a little math together while you eat another slice of pizza. Are there enough packing tractors? If there is a new employee on a packing tractor, start by having an experienced employee ride with them. Finally, develop a plan for covering the pile or bunker. Create a harvest culture of less finger pointing and more pizza.
2. Inadequate capacity: This is ranked second because as operations expand, capacity becomes a bottleneck. One chopper used to be okay, but now it’s often taking too long to chop, and dry matter targets are being missed. Bringing in a second chopper sounds good, but you need to ensure a corresponding amount of packing capacity. Following the 800-pound rule is a good starting point. This simply dictates that there be 800 pounds of packing capacity per ton of corn silage delivered to the pile or bunker per hour. It’s also critical that you have experienced pack operators (usually highly undervalued) who can get the job done.
3. Missed dry matter targets: Start monitoring crop dry matter (DM) much earlier than you think is necessary. It gets everyone on the team thinking about a target date and prepping for the labor surge. Depending on the year, soil type, and corn hybrid, the corn silage may hit the desired target earlier than what a guess on a drive by at 60 miles per hour may indicate.
I like 34% DM (66% moisture). When corn was $2.50 per bushel, I used to lean toward chopping earlier to make sure we didn’t miss the window and harvest too dry. But things have changed. As corn matures, the nuggets of gold (grain filled with starch) begin to increase in weight rapidly. Going from 30% starch to 35% starch cannot be overlooked.
Why not just let it go to 40% dry matter? As the plant matures, fiber digestibility goes down. Dairy cows need a minimum amount of fiber, and you want to maximize that fiber digestibility.
For larger dairies with seven to 14 days of chopping, hitting a specific DM percent is not easy. Monitoring DM status across multiple fields can help. Staging hybrids is a good idea, but realize that hot, dry weather can begin to squeeze your harvest window. Thinking back to previous harvests might give you a better handle on what worked, or didn’t work, in the past.
On-farm moisture testing is a standard practice on most dairy farms. Doing one sample is relatively easy, but how do you handle 10 samples? Koster testers, microwaves, air fryers, and dehydrators can all work, but each has its challenges. Perhaps one option I don’t see very often is a forced-air convection oven. It will cost about $3,000, but it’s accurate, safe, and can handle multiple samples. Spread over a lot of tons over a few years, it’s worth consideration.
4. Improper processing and chop length: I’m as good as anyone using a Penn State Particle Separator, but I don’t like to use it to measure particle length on corn silage. High-starch corn silage will have extra weight on the bottom pan, which impacts the percentages on the other pans.
I prefer using a caliper or ruler to measure the chop length on leaves and stalks, targeting 19 to 24 millimeters depending on the hybrid. Telling the harvester operator to set the chop length to 3/4 of an inch is not a guaranteed recipe for success. Measure the actual corn silage coming out of the chopper to verify the desired chop length is being achieved. Kernel processing has been much improved over the last 20 years. As with cut length, look at the harvested corn silage rather than just setting the chopper to a specific roll gap.
Setting up identical choppers the same way does not necessarily guarantee they will chop the same. Wear and tear on rollers and cutting bars can yield different results. When you change fields and as the season progresses, keep monitoring. Drier corn and different hybrids will process differently.
During harvest, sending a sample to a lab to obtain a kernel processing score isn’t going to work if your chop window is three days. An immediate, accurate analysis is needed. This requires someone with experience who knows corn silage.
5. Either not using or the improper use of inoculants: The research is clear that inoculants can reduce shrink and improve fermentation; however, research does not ensure that you purchased enough inoculant, the application equipment is working, or someone remembered to turn that equipment on.
Buy a good inoculant from a reputable company. They usually cost about 50 to 60 cents per ton. There are only about four to five companies that actually make inoculants. Buying direct from these companies will help control costs. If you have difficulty keeping up with the pile or bunker face during the year, consider using a Lactobacillus buchneri inoculant, which produces acetic acid and greatly extends aerobic stability.
This article appeared in the August/September 2022 issue of Hay & Forage Grower on pages 26-27.
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