With an eye on expanding cow numbers in the next couple of years, the Darke family decided to replace robots with a rotary parlour. Rebecca Jordan visits them to find out how the new system is working.
On average, the 200 cows at Coleridge Farm, Kingsbridge, south Devon, have achieved an extra litre-and-a-half since a new parlour was installed in mid-August.
The Darke family, which farms at Coleridge Farm, hopes the siting, design and capacity of the Waikato 44-point rotary parlour will allow them to increase cow numbers to 400 over the next couple of years without any further changes in the parlour.
This is a busy mixed farm so labour is at a premium. With 200 cows now taking just an hour to milk, there is more time for either the sheep, beef or arable enterprises.
In 2013, the farm’s 30-year-old Fullwood 17-point tribone parlour was in need of replacement. The family opted for three robots which were sited at the top end of the cubicle yard. Before long, a fourth robot was installed as cow numbers started to creep up from 180-head.
Matt Darke, who works alongside his brother Sam, their father Richard and grandfather Edward, says: “There is no doubt the robots helped us improve cow management and freed us up for work elsewhere on-farm. And they fitted very easily into the layout between the cubicles and bulk tank.
“We also had immediate access to so much data. It made us very aware how an efficient system can make such a difference to milk yield, quality and general cow wellbeing.
“However, in the past five years we have needed to increase cashflow and the most effective way our business can do this is by doubling cow numbers. With one robot only capable of efficiently milking about 60 cows a day, we needed to think again. We did not really appreciate the need for expansion when we put in the robots.”
The option of adding more robots was considered, but with maintenance costs running at £18,000/year the Darkes looked elsewhere. It was also becoming apparent that as cow numbers increased not all the cows were milking efficiently.
Low yielders tried to avoid milking, high yielders were not always achieving their full potential and the robots were not able to position clusters successfully on cows which fidgeted or had poorly positioned teats.
There has therefore been considerable investment in a fresh setup. Before a final decision was made, Matt and Sam visited a number of different parlours across the country to see what would work best for them.
The main conditions were milking time and a simple system which would allow for expansion. In the end extensive groundwork started in March at the site of the new parlour.
It is positioned at the far end of the cubicle shed with a collecting yard for 350-head linking the two. An automatic backing gate keeps an even throughput onto the parlour.
These cows are Holsteins bred to Norwegian and Swedish Red and White to improve butterfat and for hybrid vigour. Because they are bigger than the average cow in New Zealand (where Waikato orginates from), the Darkes have opted for heavy duty bails to ensure longevity.
Cows are automatically identified as soon as they step onto the parlour and are fed to yield. Cows giving less than 15 litres/day receive 0.5kg of cake with the feed-to-yield system topping at 8kg for cows giving 45 litres/day or more.
The parlour takes 11 minutes for a full rotation. This is the first Waikato parlour which has the platform’s nylon rollers orbiting between twin beams. Other parlours have the rollers resting on just one beam. The idea being twin beams will ensure the rollers wear more evenly and hence last longer.
As soon as each cow walks onto the platform, whoever is milking just needs to wipe over the teats and put on the clusters. Each bail has a small screen indicating cow number and yield. Whoever is milking can use this during milking to draft or retain specific cows.
Matt says: “The parlour speaker system indicates if a particular cow has a high cell count which ensures she is not milked in the main group.”
That cow will then leave the parlour after her rotation, but will be shedded away from the milked cows through an automated exit race with three holding pens.
This course of action is initiated by Matt or Sam on the keypad on the milking bail. These cows are then milked at the end of the session so their milk is kept separate and out of the tank.
Any cow still giving milk towards the end of the rotation will stay on for another.
Matt says: “The bail restraints stay down until they have finished milking. This is what keeps them on the parlour.
“One of the challenges of this parlour is getting cows to leave without them trying to get back on. One way we have come over this is setting up a water-jet system which fires into their faces. They can be quite stubborn.”
Clusters are removed automatically as soon as milk flow reduces. This is the first UK Waikato parlour to employ cluster drop. When the cups come off, they stay between the cows until just before that part of the parlour reaches the bridge and then automatically drop down.
Matt says: “We decided to do this because we thought it would keep the clusters cleaner and therefore reduce the herd’s bactoscan. There is also less likelihood of pulling the pipes off the cups.
“The cord holding the cluster passes through an inch-wide gap between the bridge where cows get on and off the parlour. There is a sensor each side of the bridge which automatically stops the parlour if the clusters are incorrectly positioned so they are not crushed here.”
Teats are sprayed automatically both pre- and post-milking. A pad between the cow’s hind feet houses a nozzle which sprays 14ml of iodine up onto each cow’s teats.
Milking, washing down and each plant wash consumes 4,000 litres of water from their own bore hole at each milking. This water is collected in a 10,000-litre header tank to flood wash the parlour’s collecting yard and exit race. It then drains into a new 2.5 million-gallon slurry storage.
Cows are milked at 8am, 4pm and high yielders at midnight. These will have calved less than 200 days previously, but will still give more than 30 litres/day.
“Cows do seem to be more contented than before. I do not know if that is because it is quieter in their shed now there is not the activity of 24-hour milking,” says Matt, who adds that their electricity consumption has reduced by two-thirds and is now covered by the farm’s two turbines.
Obviously cows were housed full-time when they were milked by the robots. This autumn, until housing in mid-October, just the high yielders were kept in.
Some cow tracks are still in existence, but the Darkes intend on establishing a good system to ensure they maximise yield from grazing in coming years. The idea is to move from year-round calving to outdoor block calving in late summer/autumn, with the aim of reducing the risk of spreading disease indoors over winter.
To help increase herd size, all maiden heifers are artificially inseminated with sexed semen along with some first and second lactation cows.
Aberdeen-Angus is used across the rest of the herd. These calves are finished as 20- and 24-month-old steers at 320kg to 340kg deadweight. Matt says the new milking system is working well for them.
He says: “It will allow us to expand easily. It is my grandfather’s wish to walk down the cubicles with his zimmer frame and see 400 cows here. This parlour is definitely going to help us achieve that.”