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Conductivity report catches mastitis cases earlier

Progressive Dairyman Editor Karen Lee Published on 30 September 2015

When Kiefland Holsteins in Utica, Minnesota, installed an automatic milking system in 2011, not only did the farm benefit from the reduced labor requirements – but also the steady supply of data generated by the equipment.

The Kieffers rely upon five robots to milk 300 cows in a free-flow system. They feed multiple feed types and have four full-time employees helping to manage the robots and the cows.



From early on in this new system, Chad Kieffer says the farm began watching the conductivity report. Someone on the farm checks that report twice a day to look for any deviations a cow will have from one milking to the next.

“Conductivity is not a new concept,” Kieffer says, “but the robot came equipped to generate an udder health report, showing which cows were normal and which ones were elevated.”

The cows flagged as higher-than- normal are tested with the California Mastitis Test. If the CMT test comes back at high grade, a milk sample is taken and cultured on the farm. The farm then treats the animal based upon the culture results.

They use a tri-plate culture method, which helps them determine if it is a gram-positive or gram-negative infection. For gram-positive-infected cows, they will administer a broad-spectrum antibiotic. Gram-negative-infected cows will receive a specific antibiotic as merited.

This information has led to a reduction of mastitis treatments on the farm, Kieffer says, particularly with gram-negative cases. In addition, since installing the robots, the farm’s somatic cell count has dropped from 250,000 down to 150,000 to 120,000.


Before they had access to a conductivity report, Kieffer says they were using visual detection by stripping prior to milking and CMT testing to identify cows that needed treatment. They would also reference DHIA tests, but rarely would they culture a milk sample.

“With conductivity, we can catch them sooner than visual stripping,” he says, which results in earlier treatment before the infection has a chance to progress.

The farm continues to review its DHIA report, mostly to watch for chronic cows that have a high somatic cell count but present with normal conductivity.

Kieffer says he appreciates the extra information these automated systems can generate. The farm team will also look for deviations in milk temperature, which is another report provided by the robot, and pair a high milk temperature with the conductivity report to flag cows for a closer examination.

Rumination is another report they’ll use to cross-check with conductivity. “If a cow’s conductivity is up and rumination is down, it is another red flag,” he says.

Kieffer admits conductivity is not perfect, noting it has 84 percent specificity so there will be a 12 percent rate of false positives. “We do get some false positives, so using the CMT paddle is very important,” he says.


Having access to conductivity data helped the farm tackle an issue with Klebsiella. The report enabled them to catch the infected cows sooner, which allowed them to treat the infection earlier and save those cows, Kieffer says. Now the farm vaccinates against Klebsiella and uses sand bedding, which have dramatically reduced the number of cases they find.

Kieffer notes there are a lot of new technologies in the pipeline that offer more than conductivity – such as somatic cell count measures – but he says conductivity is still an effective measure and one that continues to work for his farm.  PD

Karen Lee
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