Farming Magazine - May, 2012


A Smart Barn and a Smart "Employee"

Sixty cows and a robot
By Kathleen Hatt

Cups are attached, and the robot milks cow 436 while providing continuous data on its screen.

Mark Duffy has milked many cows in his 35 years of farming. He still has 60 or so milking Holsteins, but since January 28, 2011, he and his employees have rarely milked any of them. The cows are happy, and so is he.

That was the day the Great Brook Farm herd walked from an old tie-stall barn - built and rebuilt over many years - to a new freestyle "smart barn" nearby. The switch has brought dynamic changes to the Duffys and their cows.

First day

Family, friends and equipment reps watched as the first cow passed through an electronic gate into Great Brook State Park Farm's new milking stall. "Watching that cow being milked by a robot was like watching TV during a Super Bowl game," says Tamma Duffy. "We were glued." At the entry gate to the milking stall, a sensor read the cow's tag and entered the information in the robot's computer. Unsure of her new surroundings, the cow kicked a couple of times, and then settled in to eating grain from a tray that had moved to a height just right for her. Meanwhile, a camera that Mark helped position measured and photographed the cow's teats and stored the data in the robot's computer. After a robotic claw washed and air-dried the teats, it attached the cups and milking began. When milking was finished about eight minutes later, the cups were removed, the grain tray moved, and the cow walked through the stall and back to the herd. Meanwhile, the cups were automatically rinsed and the stall floor sprayed. (Once accustomed to the robot, cows seldom defecate while being milked.)

Cows were led into the stall until they were accustomed to the new system. By the end of the first week, and with grain as their incentive, the cows freely entered on their own. Cows are not fore-milked; the act of entering the milking stall causes their milk to drop.

An old farm looks to the future

Great Brook, a 1,000-acre family farm formerly operated by Farnum Smith, is part of Great Brook Farm State Park in Carlisle, Mass. Before the farm became the property of the Commonwealth of Massachusetts, Smith had stripped and auctioned off all the farm equipment - even its gates. When Mark and Tamma first came to Great Brook Farm in 1977 from their farm in Greenfield, N.H., they housed their 40 cows in the old tie-stall barn. However, Mark, who never milked a cow until after finishing his college degree in agricultural economics, began dreaming of better facilities.

Extensive research led him to believe the time was right for a robotic milking system and the barn to accommodate it. In 2004, he began discussing his vision with Great Brook State Park Superintendent Ray Faucher. The current park superintendent, Steve Carlin, arrived in 2007, and he continued encouraging the Massachusetts Park Department to appropriate the funds for a smart barn. The new barn would be a state-of-the-art housing and milking facility, as well as an educational experience for the public, including thousands of nearby city dwellers. The expenditure was approved in 2009.

In addition to milk, the farm also grows and sells cranberries, operates an ice cream stand, mixes and sells compost, and grows about 100 acres of corn and 170 acres of grass for haylage. Corn and grass are grown on land in four different towns. In addition to Mark, Tamma and their three children, the farm employs three full-time workers, a part-time mechanic and 13 part-time ice cream stand workers for six months of the year. From May through October an educational interpreter conducts farm tours.

A smart barn

Working together with agricultural engineer Stan Weeks and with input from other farmers and representatives of DeLaval, makers of the robotic milking system, Mark designed a "smart barn." The barn, which he likens to a highway, can house up to 120 cows and is designed to accommodate both human and cow traffic. Two electronic gates, a bulk tank and room for two robots are included in the design. The barn features thermostatically controlled inflatable sides and overhead ceiling fans. What first strikes a visitor to the barn is how quiet the cows are. "They're happy," says Mark, "and these are cows that stay in the barn." Great Brook Farm is surrounded by residences and has no space for pasture, a situation that can bring increased foot problems. The smart barn was designed to address this issue. Floors are grooved, and cows have new top-quality mattresses. They also must pass through a footbath in order to go from the robot stall to the feed manger.

From his office, Mark Duffy can analyze and manipulate data collected by the VMS robot.

In addition to state-of-the art equipment, the freestyle barn features handicapped-accessible walkways past the milking stall and around the barn. It also displays videos to acquaint the public with the complete range of the farm's activities. The Duffys hold a long-term lease on the barn from the Commonwealth of Massachusetts and own all engine-powered equipment and storage for feed and manure.

Robot at work

How much milk was expressed through each teat last milking? What is this cow's average for each teat over the last week, month or year? The robot knows.

"You have to be flexible to use this technology," says Mark. "Variations in data quickly point you to individual and herd health issues, but you could spend your days digesting and manipulating all the data the robot gathers."

A computer screen on the side of the robot displays information about each cow as she is being milked. For example, the screen showed that cow No. 436 was expected to yield 4.3 pounds of milk from each of her quarters. When milking was completed, the cow had produced 4.1 pounds per quarter, an amount within the standard deviation, according to Mark. Great Brook Farm's herd average is 86 pounds per day or about 7.2 pounds per quarter per milking.

As the robot works, it checks the milk for conductivity and color. While conductivity is not a direct measurement, it can indicate when mastitis is present. In the future, the robot will be able to test other factors in the milk at the beginning of the milking cycle. Based on those factors, it will decide whether or not to send the milk to the bulk tank.

The robot completes milking in an average of 7.5 minutes. Workers using five milking machines once took eight to 12 hours to accomplish what the robot can do in 22.5 minutes per cow per day. Working with one robot, the best operators in the world can get 6,000 pounds per day, and really good operators can get 5,000 pounds per day, according to Mark, who in his first year is getting 4,800 pounds per day.

Using data collected by the robot, Mark can identify high-producing cows and allow them more frequent access to milking. Although high-producing cows generally do go in more frequently to be milked, age, individual amounts and stage of lactation are also factors in determining milking frequency. The herd now averages three milkings per day. In the course of a day's trips through the milking stall, cows eat 6 pounds of grain. "We have to watch cows that want to enter the milking stall more than three times. They may be trying to enter only to get grain. That takes up milking time capacity," says Mark. "Those cows can be denied access at the milking stall gate." On the other hand, the gate can be programmed so that heifers can have access to more frequent milkings.

A cow stands quietly munching grain while being milked by the DeLaval Voluntary Milking System robot.

The DeLaval voluntary milking system (VMS) robot is on duty 24 hours a day, and cows can go in to be milked any hour of the day or night. In the beginning, all of the cows tended to come to the robotic milking stall at the same times they were accustomed to being milked in the old barn. "At first, we showed up at 4 or 5 a.m. to break the cows of their herding tendencies. They all wanted to be milked at the same time," says Mark. Now Mark and his workers sleep an extra hour or so unless the robot's alarm sounds to alert them to a problem. It is programmed to first call Mark. If he is unavailable, it will call Tamma and then subsequent members of the phone tree until it reaches a human. In its first year, there was only one instance when the robot could not milk a cow, and that turned out to be a problem with the camera.

By looking at the robot's control screen, Mark and his workers can see when each cow was last milked. When a cow (generally one late in her lactation cycle) has not been milked in the last 12 hours, Mark or his workers encourage her. In the beginning, they had to chase down unmilked cows and walk them to the robot. Now their mere appearance is all that is necessary to get the cow moving into the milking stall.

The pros and cons

The biggest concern is: What if the robot fails? If there is a problem, the Duffys are confident the DeLaval technician will be able to help. Via a password-protected site on the Internet, the Middlebury, Vt.-based technician routinely checks the robot's screen and its internal data and is available 24/7 should a problem occur. There is no backup robot in the Duffys' barn, and the old barn no longer has a bulk tank. The only alternative would be hand milking.

The freestyle smart barn at Great Brook Farm was designed to house up to 120 cows and two robots.

Normal milking system maintenance, such as changing filters, is accomplished while the milk truck driver is emptying the bulk tank, a 90-minute period every two days. During that time, only one cow can be milked.

Mark likes the system's enormous diagnostic capability. With data the robot provides, he can actively monitor all of his cows. He can even tell when each cow comes into heat. The robot's screen shows the expected activity level for each stage of lactation. When a cow is in heat, her pedometer will indicate that she is walking way more than average. "Robots raise your level of management so you focus attention on cows that need attention," says Mark. "The robot will take care of cows that don't need specific attention."

Great Brook Farm experiences all the advantages and disadvantages of any facility open to the public. With 100,000 people utilizing the park annually, many eyes scrutinize the farm's practices. Because the herd is not pastured, some people raise issues about animal welfare. Some suggest the farm is responsible for the neighborhood's annual invasion of Asian beetles. "Despite the occasional challenges, members of the public are our greatest supporters," says Mark. "We are committed to helping the public understand where milk comes from and to appreciate the contributions of agriculture to their lives."

Kathleen Hatt is a freelance writer and a frequent contributor to Farming. She resides in Henniker, N.H..