TMR Mixer Sizing Guide

If you are shopping for a TMR vertical feed mixer for your dairy operation, the most important decision is not which brand to buy — it is what size to buy. Get the size wrong and you are either overpaying for capacity you do not use or running multiple loads where one should do. This guide will walk you through the math and the practical factors that matter most for northern Indiana dairy farms.

Why Size Matters More Than Brand

A well-sized mixer from a mid-tier brand will outperform an undersized mixer from the best brand on the market. When a mixer is loaded above capacity, the auger cannot turn material properly, mixing consistency suffers, and you put excessive wear on the gearbox and drive components. When it is oversized for your herd, you waste time, fuel, and money on every batch.

The Basic Sizing Formula

The most common rule of thumb used in the industry is 1.5 to 2.0 cubic feet of mixer capacity per cow per load. So if you are feeding 150 cows in a single load, you need a mixer in the 225 to 300 cubic foot range. If you split your herd into two groups — a fresh cow group and a far-off dry group, for example — size for your largest group.

There are several factors that can push you toward the higher end of that range:

High-moisture silage or wet byproducts take up more volume per unit of dry matter
Rations with a high percentage of long-stem dry hay need extra headroom for the hay to fold down as it mixes
Operations feeding multiple times per day may find a slightly smaller mixer fits better into their workflow

Vertical vs. Horizontal — Does It Matter in Indiana?

For most northern Indiana dairy operations, a vertical mixer is the right choice. Here is why: northern Indiana dairies often use a meaningful percentage of dry hay in their ration, particularly operations that also harvest their own hay. Vertical mixers — including the Penta line we have carried since 2001 — handle long-stem hay without pre-processing. You can drop bales directly into the mixer and the vertical auger will break them down and incorporate them into the ration.

Horizontal mixers are faster and work well with pre-processed or finely chopped ingredients, but they struggle with whole bales and long-stem material. If your ration includes any meaningful percentage of dry hay, vertical is almost always the right call.

What About Older Herds vs. Growing Operations?

If you are planning to expand your herd in the next three to five years, buy for where you are going, not where you are today. A mixer that is slightly oversized for your current herd is far less costly than replacing your mixer in four years because you outgrew it.

Getting a Specific Recommendation

The Martin family at Wakarusa Ag has been selling Penta TMR mixers since 2001 and runs dairy cattle themselves. If you tell us your herd size, your ration composition, and your feeding schedule, we can give you a specific size recommendation and walk you through the available configurations. Call us at 574-862-1163 or stop in at 905 Nelsons Parkway in Wakarusa.

Why Choose UsWhy Choose Us

Research has shown that when a farmer is looking to buy a new piece of equipment for their farm the first step is to talk to a dealer and see what choices are available. The next step is to talk to a neighbor or a farmer in a neighboring area or state to get their opinion. It’s important to know what size of equipment you need. It’s also important to consider if you are looking for a moderately priced brand or are you willing to pay a premium for one that meets the highest standards of the industry.

When you shop at Wakarusa Ag, their team will be taking all those factors into consideration alongside you. They are uniquely qualified to answer your questions because they have experience as farmers, dairymen, livestock producers and equipment retailers. When you are looking for new equipment, rest assured, you will get expert advice from Wakarusa Ag.