by Blake SandnesGetting the right corn particle size starts with using the right testing method. According to Josh Tracy (R&D) and Blake Sandnes (General Manager) at RMS Roller-Grinder, most operations use one of these three tools:
- Hand Sieve Test: A quick field method using three stacked screens. Great for spot checks, but not the most precise.
- Ro-Tap Testing (13-Screen Sieve): The go-to standard in feed production. It uses 13 screens and optional flow agents to deliver detailed, lab-quality particle size distribution.
- Automated Systems like the RMS ParticlePro®: This real-time tool measures particles as they exit the mill, providing constant, accurate data that helps users make fast adjustments.
As Blake puts it, “Quick spot checks are useful, but if you’re aiming for feed consistency and animal health, the 13-screen or real-time systems are where you’ll get real accuracy.”
How Accurate Are These Methods?
Each method has its place, but their accuracy levels vary:
- Hand sieves have a margin of about ±100 microns, heavily influenced by who’s doing the shaking.
- Ro-Tap systems tighten that range to around ±50 microns, and even better (around 35 microns) with a flow agent.
- Automated systems like RMS’s ParticlePro provide the most reliable results, especially for continuous monitoring.
To put it in perspective: a single micron is one-millionth of a meter—about 70 microns is the thickness of a human hair.
“If you want real control over your grind,” Josh says, “especially when switching grain sources or adjusting settings, real-time systems can save you both time and money.”
What’s the Best Way to Measure Corn Particle Size?
It depends on your goals. If you’re doing a quick check in the field, a hand sieve works. But if you want to improve feed efficiency, animal health, and cost control, use a Ro-Tap system or an automated tool like the RMS ParticlePro.
Just as important as choosing the right tool is using the same method every time. Switching between testing methods—like comparing Near Infrared (NIR) analysis with Ro-Tap results—can throw off your data. Some labs use flow agents during testing to improve flow through the sieves, often resulting in micron sizes that read 75 to 80 microns lower.
If you don’t adjust for that difference, your numbers may look inconsistent when nothing has actually changed. That can lead to bad decisions and poor feed performance.
Josh says it best: “Pick a method and use it consistently. That’s how you get meaningful trends.”
Why Corn Particle Size Matters for Animal Feed
Corn is central in most livestock diets, so how it’s ground has a major impact on feed conversion, digestibility, and overall performance. When particle size is too coarse, animals miss out on valuable energy. When it’s too inconsistent, gut health can suffer.
Research shows that for every 100-micron reduction in corn particle size, producers can improve feed efficiency by up to 4 points in swine and around 1% overall. Grinding finer doesn’t cost more per bushel, but it does allow animals to extract more energy from the same feed.
Blake adds, “Poorly ground corn—whether too coarse or too variable—can mess with animal gut health and feed flow. Monitoring it weekly can prevent huge issues down the line.”
Even if your average is right, your standard deviation matters. A 500-micron sample with uneven particle sizes can still perform poorly. That’s where specialized equipment choice comes in.
Roller Mill vs. Hammer Mill: What Delivers Better Consistency?
Both can reduce corn particle size, but the mechanics and results differ.
- Hammer mills crush grain forcefully. They’re ideal when you need ultra-fine particles (like in pelleted diets), but they often create a wide spread of particle sizes, which can cause flowability issues and hurt feed performance.
- Roller mills shear grain instead, producing a tighter, more uniform grind with fewer ultra-fine particles. This consistency is key in meal feeds and helps support animal gut health.
Blake notes: “Roller mills reduce fines and oversized particles, giving you better performance in mash diets and fewer feed flow issues.”
For most operations seeking steady performance and fewer issues, a corn mill grinder with roller technology is the smart choice.
RMS Can Upgrade Your Feed Strategy
Dialing in your corn particle size could be the simplest (and most profitable) upgrade you make this year. With RMS’s tools—like the ParticlePro System—and expert support from people like Josh and Blake, you’ll stop flying blind and start feeding smarter.
Want to improve your grind strategy? Let’s talk. Request a quote or reach out to learn how RMS can support your operation.
