The Science Behind Total Mixed Ration Success
Creating the perfect Total Mixed Ration (TMR) for dairy cattle is both an art and a science. Proper mixing isn't just about combining ingredients—it's about precision, consistency, and knowing how your equipment functions. Dialing in on the speed and time settings specific to your vertical mixer and your herd’s TMR will produce a quality mix. Delivering a quality mix will impact your milk production, herd health, and ultimately, your bottom line. Three variables that impact the TMR mixing process are:
● Speed
● Time
● Auger
When these parameters are properly calibrated, you'll achieve consistent, homogeneous feed mixtures with nutritional integrity.
MIXING SPEED: When to Shift Gears
Vertical mixers typically offer two speed settings—low and high gear. Each gear serves a distinct purpose in the mixing process:
Low (1**st) Gear:**
This setting provides maximum torque with slower auger rotation speeds, typically ranging from 20-30 RPM. Low gear is commonly used for:
● Loading of dense, heavy ingredients such as silage and hay
● Breaking down and processing large hay bales or long-stemmed forages
● Breaking up frozen or clumped ingredients
● Handling high moisture loads that create resistance or might splash at higher speeds
● Final mixing to ensure thorough ingredient incorporation without overmixing
● Engaging the PTO under full load when the mixer has been idle.
Low gear allows the mixer to handle heavier loads while maintaining consistent power. The reduced speed also minimizes particle size reduction, preserving the physical effectiveness of fiber in the ration.
High (2**nd) Gear:**
High gear operates at faster RPMs but with less torque. This setting works best for:
● Mixing lighter, pre-processed ingredients that flow freely and require less torque
● Blending in supplements, minerals, and other micro-ingredients
● Situations where time efficiency is critical*
● Faster unloading, or cleanout, of the finished TMR
Knowing when to shift gears can significantly affect mix quality. Start in high gear when loading dry ingredients, premixes, and processing. Once dry materials are blended or broken down, shift to low gear for final blending.
Note: Avoid over mixing! Some operators attempt to mix from feed-pad-to-feed-alley in high gear, to avoid shifting to low to restart the mixer underload. This practice degrades physically effective fiber (peNDF). When the mix is completely mixed, stop the mixer when not immediately feeding out.
*High gear can reduce total mixing time. If used too extensively (such as mixing or startup under full load), will stress tractor and mixer and lead to premature wear.
MIXING TIME: Finding the Sweet Spot
Mixing time, like mixing speed, affects TMR. Under or overmixing can create issues.
Undermixing results in:
● Inconsistent nutrient distribution
● "Hot spots" of concentrated supplements or additives
● Sorting of feed
Overmixing leads to:
● Excessive particle size reduction
● Damage to feed particles, particularly forages
● Decreased peNDF
● Digestive issues
As a general guideline, most TMR mixes require:
● 3-5 minutes in high gear for initial processing
● 2-4 minutes in low gear after the final ingredient for final blending
However, these times may vary based on:
● Ingredient moisture content
● Forage length and type
● Mixer capacity utilization
● Specific auger design
The best approach is to monitor your mix visually and adjust timing based on your specific ingredients and equipment. For most dairy feed mixtures, aim for approximately:
● 100-150 total auger revolutions for a complete mix
● This translates to roughly 3-5 minutes at 25-35 RPM
AUGER DESIGN: The Differentiator between Mixers
One of the biggest differences between vertical mixers on the market are auger configurations. The auger design is what differentiates the vertical mixer manufacturers. Considered the heart of the mixer, the auger design significantly influences how ingredients interact during the mixing process.
Auger Components that Matter:
Let’s look at the individual auger components and the role they play in mix quality.
● Auger Flighting: This spiral blade moves feed vertically. How fast the feed moves through the mixer is based on the pitch and spacing of the flighting. Wider spacing moves material faster but may sacrifice mix uniformity.
● Knives & Kickers: Mixer knives help process longer materials. The placement and number of knives affect how thoroughly fibrous ingredients are processed. Kickers prevent "dead spots" in the mix and aid in faster cleanout.
● Auger Speed: This works in conjunction with the mixer's gear settings. The optimal auger speed varies based on load size and ingredient composition.
● Auger Height: Taller augers can handle more material but may require more power. The height-to-diameter ratio affects mixing efficiency. Shorter augers limit spillage when processing long hay, but may affect mix quality.
The right auger configuration depends on your specific feeding program, ingredient types, and operational requirements.
Single vs Multiple Auger Mixers
In addition to the auger design, the number of augers in the mixer play a role.
Single-Auger Mixers:
● Small to medium operations
● Basic rations
● Typically require less horsepower
● May need longer mixing times
● Often have larger capacity per auger
● Commonly direct-drive with no 2-speed gearbox.
Twin or Triple-Auger Mixers:
● Large operations
● Complex rations
● Create more mixing action with multiple mixing zones
● Generally, achieve uniform mixes in less time
● May process hay and long-stem materials more efficiently
Putting It All Together
Speed, time, and auger design all need to be in-sync to create an optimal TMR. Since every operation and ration is unique, finding that balance of what works for your operation will take some trial and error. Observe and adjust. Here are practical steps to help you find the time and speed settings that will deliver an optimized TMR tailored to your herd.
1. Check with the manufacturer. Find out what they recommend for your specific model.
2. Observe. Monitor feed particle consistency throughout the mix.
3. Evaluate. Is there feed sorting going on at the bunk?
4. Adjust. Tweak the settings in small increments until optimal results are achieved.
Evaluating Your Mix: What to Look For
Regular evaluation of your TMR is essential. A properly mixed TMR should demonstrate:
● Consistent Particle Distribution. When sampling from multiple locations in the mixer or feedbunk, each sample should look visually similar.
● Uniform color throughout the mix
● Even Nutrient Distribution: Supplements and smaller ingredients should be evenly distributed with no visible concentrations.
● Consistent Moisture: No dry pockets or overly wet areas throughout the mix.
● Minimal sorting Potential: When delivered to the bunk, animals should not be able to easily separate components.
● Proper Particle Length: Forage particles should maintain appropriate length for rumen function while being short enough to prevent sorting.
● Feed and TMR Testing: Develop feed and TMR testing protocol to regularly sample ingredients and mix through local laboratory analysis.
● Particle size separators or "Penn State Particle Separators" can help quantify particle distribution to ensure your mixing protocol is achieving the desired results.
A practical test: Take samples from different locations in your mixer or feed bunk. Spread them on a flat, dark surface and look for consistency in color, particle size, and ingredient distribution.
Benefits of Being Balanced
Optimizing your mixing process doesn't just improve feed quality—it saves time and labor. When your mixer is properly configured and operated, you'll experience:
● More consistent feed quality
● Less waste - feed sorting is reduced
● Preserved nutritional value and particle length
● Lower equipment wear and fuel consumption
● More predictable milk production or weight gain
● Reduced mixing time requirements
Equipment Maintenance Considerations
To keep your mixer working at peak efficiency and optimal levels, practice proper equipment maintenance. Dull, damaged, or worn components can significantly impact mixing performance regardless of speed and time settings. Regularly inspect auger knives, kicker plates, and other wear components. Repair or replace components as necessary.
Perfect Ending
The perfect TMR mix comes from understanding the interplay between speed, time, and auger design. By mastering these variables, you can achieve consistent, high-quality mixes that promote animal health and productivity while maximizing operational efficiency.
For more information about optimizing your feed handling equipment or to learn about Patz vertical mixer options designed to save you time and labor, contact us at 1.920.897.2251 or visit patzcorp.com.
Lee Enterprises newsrooms were not involved in the creation of this content.
