Minimizing “false positives” is also a work in progress for researchers studying these technologies.
“One of the most important things that we have to recognize with any kind of alert system is that balance between sensitivity and specificity,” Bewley says. “Basically, we want to be able to detect whatever we’re looking for (mastitis), but we also have to make sure the alerts don’t have a lot of false positives.”
For example, say you have 20 cows come up on a daily alert list, but only two of them truly have mastitis. You just spent an unnecessary amount of time working with those other 18 cows that didn’t need your attention.
“The false positive rate is something that we really need to look at,” Bewley says. “There’s a balance between catching it and getting false positives, and the two are always fighting against each other.”
What else is out there?
Technology that uses rumen boluses to detect sick cows is just one of several tools that could serve as an alternative or supplement to common cow-side mastitis tests.
Here’s a brief look at some mastitis-detection technologies that are already available or in the pipeline.
• Electrical conductivity measures the concentration of cations and anions in milk, which undergo changes when a cow has mastitis. This technology has been around for several years.
• In-line sensors in the milking system that essentially automate SCC sampling have been commercialized in Europe and New Zealand.
• Biosensors detect the milk enzyme L-Lactate dehydrogenase (LDH), which is released during an immune response and serves an early indication of mastitis.
• Behavior-monitoring systems assess how much time a cow spends lying down. A change in resting behavior may be an indication of impending illness, including mastitis.
Application of any mastitis-detection technology needs to be well thought out, Bewley cautions. See what’s available to you and ask some tough questions about the system’s detection capabilities before investing in it.