Robots Are Milking Cows for Dairy, Data

​Across the midwest, an increasing number of dairy farmers are bringing a new helper to the farm: cow-milking robots. Aside from making milk collection more efficient, they may soon provide better-than-ever insight into the health and behavior of dairy cows by collecting reams of detailed data during the milking process.

Milking has been semi-automated for decades now, but it still requires a human to corral the animals, clean the cows' udders, and hook up and detach the milking machine. Robotic milkers eliminate the need for human intervention: it's just animal and machine.

Here's how it works: cows are trained to expect a serving of special feed when they enter the milking machine. When a cow decides it wants its treat, it makes its way to the robot. Marcia Endres, a professor of dairy science at the University of Minnesota, called this "the cow getting her candy." Once the cow pushes past the gate, the machine scans an ID tag on the her collar and distributes some feed. While Bessie eats, robotic arms detect her udder and, using either a laser, a 3D camera, or a combination of the two, locate her teats to attach the milking cups.

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"Once it finds the teats a few times on the cow, that cow is in the memory of the computer so every time it's a little bit easier for the machine to find the teats," Endres said.

The machines are expensive. They start at $180,000 for a unit that can milk 60 cows a day, but usually require renovations and retrofitting in order to install, which bumps up the price tag. Most mid-sized farms have between 120 and 200 cows, so the total cost can end up pushing $500,000, Endres said.

But they're considered an investment. Not only can the farmer get other work done during milking time without having to hire extra help, they can be more flexible with their schedule as well. It's also a good way to attract next generation, tech-savvy farmers to the field.

Still, what really intrigues Endres is what the robots can teach us about cow behaviour. She and her colleagues have been collecting data from 52 different farms across Minnesota and Wisconsin that are currently equipped with milking bots. The bots collect data points from each individual cow each time they are milked (cows are milked one to four times per day, depending on the cow), from the time of day they choose to get milked, to how much milk they produce, to how much food they ought to be eating.

Since the cows choose when to get milked (traditionally, all the cows are gathered and milked at the same time), she's particularly interested in looking at the time of day when different cows are being milked.

"Younger animals who have just had their first calf, are they a little more shy of getting milked? Are they going at different times of the day than the more mature, larger animals? Is there some competition going on?" Endres said. "Is there a routine? Do certain groups of cows go at the same time because they're pals and they always hang out together?"

She also said they have data about the barn spaces to compare with the robot data: are larger, more open barns yielding more milk than those with tighter quarters?

While they work through the data, Endres and her colleagues have been visiting and interviewing the dairy farmers to get some anecdotal feedback on the machines. She and the farmers have both noticed calmer, happier cows, though she noted that's difficult to measure and prove scientifically.

Since they started the study two and a half years ago, Endres said she's seen dozens of more farms installing the robots, estimating about 150 dairy farms now have robots in the midwest and northeast. They haven't really been popularized out west, she said, where dairy farms are typically much bigger and a one-at-a-time milking approach wouldn't be efficient. But for smaller family farms—and researchers like herself—they're an exciting new piece of farm technology.