Delivering consistency from one end of the feedbunk to the other begins with the right TMR mixer. With different styles and sizes available, choosing the mixer that best meets your dairy’s needs can be a challenging task.

Doug Williams, Kuhn North America, walked through the basics of choosing a TMR mixer at the Vita Plus Dairy Summit.

“Your TMR mixer is one of the most important management tools you have for feeding your dairy or livestock animals,” said the field support, shows and training manager of the agriculture machinery manufacturer.

Mixer basics
Williams outlined three types of mixers: rotary/reel mixer, horizontal auger and vertical mixer.

The rotary or reel mixer involves one large, slow-turning reel, along with two augers, to blend material forward and backward. The combined lifting action makes for a fluffy, more palatable ration. These mixers are commonly found on both dairies and beef finishing lots.


They are not designed to handle round bales, but they can accommodate up to 20 percent long-stem hay. If minimal processing is required, the reel or rotary mixer is the best choice because of mixing speed and horsepower requirement.

The horizontal auger creates a front-to-back, up-and-down cycling action with its configuration of upper and lower augers. In contrast to the fluffing action of the rotary or reel mixer, the horizontal auger has more of a forcing and squeezing effect.

It can handle a higher portion of long-stemmed fiber (up to 30 percent), and it does the best job of the three at mixing sticky material like molasses. While considered a low horsepower machine to operate, it is typically more expensive to purchase than the others.

In the vertical mixer, one or two large vertical augers are the driving force to mix feed. These units are the best equipped of the three options to handle large square bales, round bales and other long, unprocessed fiber sources. For this reason, they are not as well suited for mixing low-roughage diets, such as calf rations.

Vertical mixers have higher horsepower and fuel demands than other options; however, when compared to horizontal and reel mixers for bale processing, vertical mixers capture efficiencies.

Choosing the right size TMR mixer
Determining the correct size TMR mixer comes down to some fairly simple math, Williams explained.

Sizing should be based on volume (cubic feet), not weight. A typical dairy cow will consume 5 to 7 cubic feet of a TMR ration per day. This is the equivalent of about 5 cubic feet per day for diets consisting of cut haylage, corn silage and no long-stem hay.

Diets including 2 to 3 pounds of long-stem hay per cow per day for rumen health can be estimated at a volume of 6 cubic feet per day. The higher limit of 7 cubic feet per day can be used for processing larger amounts of long-stem hay.

Using these numbers, take the maximum group or pen size you will be feeding and multiply it times the proper cubic feet. Then, divide it by the number of times per day you plan on mixing and feeding.

200 cows x 5 cubic feet per cow = 1,000 cubic feet
1,000 cubic feet / 2 feeding per day = 500 cubic feet
In this case, a minimum 500 cubic foot mixer is required.

“Choose the right type of mixer, choose the right size, choose the right configuration, use the mixer properly, inspect and maintain that mixer, choose and manage the scale system,” Williams advised. “ Let’s get the most we can out of every ration.” PD

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Peggy Coffeen
PD Staff

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