When Dairy News Australia visited in early December he was about to put in the eighth Lely robot and his third in-shed Cosmix automatic feeder.
Henningsen used to milk 250 cows up until June 2010. He is now about to milk 500 and virtually on his own.
He looks after all the milk harvesting process by himself, with one casual helper coming in three days a week, mainly to clean down and move around the milk for the calves.
"I'm always here with the heifers but I'm now free to look after the calving and other priorities," Henningsen said. "I don't have to put the cups on."
He admits that it hasn't got much easier.
"You're learning what the cows are learning. We are not hands-on, not seeing every cow, so you pay more attention to the computer, particularly in picking up the signs of environmental mastitis.
"I spend more time on the computer than I do in the shed. The more you're on it, the more you get used to it."
The milking shed is a very open affair with a high flexible roof for better light and air flow.
Henningsen's original seven Lely Astronaut robot milkers were commissioned all at the one time in June 2010. This latest installation is the fifteenth Lely robot milker installed by Dairy Tech South East of Mt Gambier, spread over three local dairies.
It's been a fairly steep learning curve for Lely Australia as well as the dealership and the farmers.
Dealer principal Rob Ciavatta said the milking process is "absolutely perfect".
"For instance, yesterday the robots milked 1000 cows with just two failed milkings.
"Rob Henningsen is our oldest automatic calf feeder customer and has had an absolutely exceptional run. He now has two feeders, each with four stations and is feeding 450 calves at any one time."
Training for the robots involved walking the cows through the units with feed to get them used to it, and allowing the computer's memory to locate the teats and match them up with each cow's neckband transponder.
Both Ciavatta and Henningsen said they were surprised at how quickly the cows learnt and accepted the system.
Jurgen Steen is Lely Australia's manager for dairy equipment and he explained that a milk line configuration unique to Australian dairies is to cater for our seasonal calving system.
They have set up a preventative maintenance schedule where each robot is serviced three times per year, plus Lely Australia provides a 24 hour support team.
Henningsen's rationale behind this level of automation was to build herd numbers and individual production levels.
He said the original decision to go for robots was to solve the problem of labour.
"Trying to get people to work in the dairy was very difficult. We had to find a better way. Plus, instead of having cows standing around busting with milk they can come up any time to be milked."
When he was thinking about the upgrade he went to see Simon Scowen's five robot milker installation at Kongorong, south west of Mt Gambier.
"My main worry was putting the cups on, but it did it very efficiently, using lasers to locate the teats.
"This system realises the full potential for the individual cows.
"Grain is fed evenly throughout the day, which has to be better for digestion and production. Since we put the system in we had a good year last year getting cows in calf."
The cows can come up any time of the day – as often as they like – to be milked, and can then go to one of the automatic feeders close by the robots in the shed to get their total mixed ration.
If the neckband reader recognises that they have been milked within the previous four hours, it drafts them away from the robot to either the feeders or back out to the paddock.
Each robot milks 20 hours per day and harvests 2000 litres.
A 1600 litre buffer milk tank system allows the robots to keep operating while the tanker picks up from the main vat. Ciavatta said this had been the only real area of service issues.
The robot's readout includes a conductivity indicator for mastitis and they are working on fat and protein level measurements, which will come with the latest new machine.
The automation has meant that paddock management has become of prime importance and Henningsen has needed to become very proficient at that.
He admits that he is still learning.
"We divide the property up into four paddocks, three grazing and one drafting, appropriately named A, B, C and D.
"At any one time there are cows in all three grazing paddocks.
"They are continually being drafted onto a fresh paddock. It has taken 12 months to work out grazing rates."
They work on a high feed ration based on the cow's production, ranging from 9kg/day for the heifers and up to 15kg for the high performers.
The best cows currently produce between 62 and 70 litres per day.
