A smoothly running robotic milking operation requires more than just the right brand of robot. Laying out the barn in a suitable way can make the experience much more comfortable for both the barn dwellers and their owners.
“The cow really doesn’t care what type of milking is going on,” John Tyson, a Penn State agricultural engineer, said. “Her production is not dependent on how we milk her.”
Tyson and Jeff Prashaw, project design manager for automatic milking at DeLaval, spoke during a Penn State Technology Tuesday webinar on Nov. 26.
Farmers should understand that the bells and whistles of robotic systems are for improving management, not interesting the cow. Barn design needs to consider the cow’s perspective and should easily provide her needs, Tyson said.
Ideally, half the cow’s time should be spent lying down, whether ruminating, sleeping or resting. Eating and drinking take another quarter of the day. Milking should take about three hours, maybe a little less in a robotic system, he said.
Dairy barns are generally positioned so that the prevailing winds can move air through the barn without obstruction. The location of a robot should take that into account.
“Make sure it’s not (built on) the prevailing side, for sure,” Tyson said.
Water is the single largest feed ingredient. Cows do not spend a large share of their day drinking, but when they do, they can drink 3-5 gallons per minute.
“They can put away a lot of water in a short amount of time,” Tyson said.
Tyson recommended a 30-50 gallon tank, as it is small enough to keep clean but large enough to supply several cows at a time. At least two waterers should be available per group.
Most cows prefer to drink while eating and after being milked, and the water needs to be situated to allow several cows access at a time.
Water and feed need to be readily available, but they should not be in the waiting area for the cows to access just before milking. Cows do not need to get too comfortable in the waiting area because they will not be there very long, Tyson said.
If anything, the waiting area floor could have a more forgiving surface, like rubber, he said.
Keeping waiting times short is key, and that is more of a management issue than an architectural issue, he said.
Choosing a type of flow is also important, said Prashaw, the DeLaval project manager.
“We can’t just put a robot in the middle of a barn and expect the cow to comfortably get there,” Prashaw said.
Free-flow setups are “by far the most popular,” Prashaw said. Cows can walk over to the feed bunks, stalls and robots at any time they choose.
While free-flow barns require a smaller capital investment than systems with more gates and structure, free-flow barns have greater need for fetch pens. Farmers use these to round up the cows, usually timid or late-lactation animals, that do not want to be milked.
Guided-traffic systems, by contrast, sequence cows’ activities. The two main types differ in the order of activities.
In a milk-first guided-traffic system, cows are sorted as they move from the stalls to the feed bunk. The sort gate, using smart ear tags and data the robots have collected during milking, sends them either to the commitment pen to be milked or to the feeding area.
Milk-first systems require the least amount of incentive feed, 2.5-4 pounds per cow per day, at the robot of any system. The cows can only eat after they get milked, which gives them an additional reason to get milked, Prashaw said.
Milk-first is a good option for people who feed a high-energy ration like corn silage. The special feed at the robot will not be very different from the regular feed, but going through the robot to get any feed is a sufficient incentive to go through at all, he said.
In a feed-first guided-traffic system, cows move directly from their stalls to the feed bunk. They visit the robot afterward.
A modified version of the feed-first model, popular in Ontario, sends the cows back to the bunk, not the stall, after milking, Prashaw said.
Because cows in feed-first systems are already in the feed alley when they have to get milked, they can get lazy and want to lie down in the feed alley instead of going through the robot. Cows require a much larger grain treat, 8-12 pounds per cow per day, to go through the machine in a feed-first system, which can raise feed costs, he said.
Dairies with forage-heavy rations might have an easier time than others, though, because the grain at the robot has more energy than the cows’ common feed, he said.
Both types of guided-traffic system give farmers greater control over their cows’ movements. They save labor because gates and pens control the cows’ movements, making for fewer cows to fetch than in a free-flow system.
Guided-traffic systems use the robots efficiently because they only allow cows into the robot if they are due to be milked. As a result they can put more cows through the robots and can serve larger herds.
Guided-traffic barns are more expensive to design and build than free-flow barns because of the extra gates and structures.
Hybrids of free-flow and guided-traffic systems should occur only in retrofitted barns, Prashaw said. Such setups typically use space inefficiently, shoehorning gates and pens awkwardly into the barn’s existing structure, he said.
If a farmer is set on retrofitting, a free-flow systems is probably better, he said. They allow better cow flow and do not require as much equipment to be crammed into the existing space.
Commitment pens in guided-traffic barns should offer 35-40 square feet per cow, Prashaw said.
Waiting areas in free-flow barns should leave at least 23 feet clear in front of the robot. Just like humans, cows can be reluctant to get in line if it looks crowded, he said.
A fence alongside the robot keeps other cows from nosing and bothering the cow being milked, he said.
Both spaces should be neither too large, which tempts the cows to lie down, or too small, which stresses the animals, Prashaw said.
The wait for milking should be limited to 45 minutes or six cows.
“We love exit lanes” out of the robots, Prashaw said, because they keep just-milked cows from mixing with those who are waiting their turn.
Farmers need to ask, “Is this a one-person job?” when sizing their fetch pen, he said.
Farmers should see if they will be able to fit all of the fetched cows into the pen at one time. At the same time, the fetch pen must not impede the on-time cows’ access to the robot, he said.
To further relieve congestion, foot baths are best located in the robot exit area or away from the milking area, he said.
Spreading new bedding on the pack can be challenging in free-flow systems because the cows are allowed to lie down at any time.
One Canadian dairy solved this problem by having a wagon on a track above the pens that snows straw on the pack all day, Prashaw said.
The farmer could also move all the cows into the feed alley while he replenishes the pack. “That might be a good way to attack it,” he said.