As professional businessmen and businesswomen, dairy producers battle with the costs of running their operation on a daily basis.

One such routine cost is the purchase of liners. With countless options on the market – each making unique performance and length-of-life claims – it’s important that producers understand the true value and cost of the liners they choose.

Too much emphasis on cost, performance or material could cause you to make short-sighted decisions and end up causing more problems in the long run. Debating the merits of all three helps pinpoint the right solution for your dairy.

Material

Consider some facts and historical data on liner compounds that are constant no matter which company manufactures them. A variety of compounds are blended to become what you see as a finished product. Making a rubber compound is very similar to baking a cake. Add too much, or too little, of one ingredient, and it might become too stiff or soft. It might also become unable to withstand routine as well as harsh cleaning and sanitation chemicals.

Since the invention of the “modern” milking machine in the early 1900s, natural rubber was the most popular material used. As dairy herd sizes grew, producers demanded longer-life products. This shift ushered in a host of new liner options designed to help reduce changes, which most agree is the least favorite dairy chore.

In order to meet producer demands for longer-life products, manufacturers had to make compound changes. It is virtually impossible to go beyond 800 to 1,000 milkings when using 100 percent natural rubber. As a result, synthetic rubbers are now the main compounds used in liners labeled as “rubber.”

Synthetic rubbers offer longer service intervals (as compared to natural rubber) as well as other benefits like better resistance to chemicals and ozone. Many manufacturers offer “extended-life rubber” products, which traditionally milk slower as compared to their “standard-life” counterparts. However, there are liners that claim to show no difference in milking performance between standard-life and extended-life inflations.

One such option is silicone, which offers an extended life but has several technical drawbacks. Silicone is more prone to cutting (especially around the nipple attachment on the claw) and butterfat migration issues. These issues can actually shorten its claimed length of life and affect overall performance. They are not always reflected in a manufacturer’s recommendations and are usually discovered as the result of a failed inspection by your local milk inspector.

Other components commonly found in rubber liners are FDA-approved phthalate plasticizers, which soften the rubber compound. However, as reported by the U.S. National Library of Medicine, phthalates are a suspected carcinogen and may be linked with some instances of breast cancer. Additionally, they are suspected to affect hormone levels in young children.

As a result, some manufacturers have eliminated phthalates from their rubber, silicone and PVC compounds in an effort to be more socially responsible. If this concerns you, ask your route driver if the liners you use contain phthalates. If they do, perhaps your specialist can recommend a phthalate-free option.

Costs

Costs are important to producers, no matter how large the herd. A common misperception is that most liners have similar lengths of life. This, however, is not true. Since lifetimes differ, the true total cost of ownership is found when comparing its cost per milking. When put in this framework, the shorter-life liner may actually be more expensive than a longer-life option.

The longer-life liner might appear more expensive because of the up-front costs at the time of purchase, but a longer life means you are paying less often. With this in mind, it is important to calculate the costs per milking on inflations and compare the options. The following formula helps determine the cost per milking: 

Cost per liner / Manufacturer-suggested liner life = cost per milking.

Using the above formula, Table 1 shows some examples of the effect of liner life on “actual cost.” In this chart, “Liner B” results in the best price for the producer.

Part of the reason for the differences comes back to the materials used. When I visit dairies, producers often ask about liner life and material compounds. Many believe all compounds are the same or state they will use natural rubber or silicone because they believe the material is superior. The reality is: Material affects performance, which in turn affects costs.

Performance

At the end of the day, regardless of the material or length of life, the liner must perform well. Generally speaking, performance for most producers means a liner must milk quickly (low machine unit on-time), not slip too much and be as gentle as possible. Gentleness should always enter the equation, as rough or irritated teat ends will lead to a decrease in production.

“Gentleness” is a balancing act, considering factors such as vacuum and pulsation settings. To address this, manufacturers have come up with liner variations and shapes to attempt to strike a design balance between milking speed and gentleness. These two factors often tend to counter each other, but other properties such as low slip or completeness of milkout can be added to the design.

Shaped liners, such as square or triangle, fall into this category as they typically are promoted as helpful in reducing hyperkeratosis but may sacrifice milking speed. Recent research shows that the best of both worlds can be found in a triangular liner with rounded edges that grips the teat well, preventing slips while promoting teat health with a low mouthpiece vacuum. At the same time, this design milks quickly and completely.

Conclusion

In the end, every liner on the market can get milk out of your cows. However, the focus should remain on choosing an option that is best suited for your expectations and system settings. Knowing your true cost per milking, understanding the value in a liner’s formulation and the performance associated with various shapes can help play a vital role in your productivity.

As the struggle continues to control costs while maximizing output, determining the right liner should be paramount. Liners play an important role on your dairy; do not consider them an afterthought.  PD

PHOTO: Every liner on the market can get milk out of your cows, so choose an option that is best suited for your expectations and system settings. Photo provided by DeLaval.

References omitted due to space but are available upon request. Click here to email an editor.

Nathan Brown is a native of central Illinois and grew up on a commercial row-crop farm focused on corn and soybean production. He is the solution manager, liners and tubes for DeLaval Inc., and manages the marketing of other consumables. Brown holds a bachelor’s degree in agricultural business management and a master’s degree from the University of Illinois – Urbana Champaign. You can reach him by email.