Convincing a cow that it’s OK to step onto a moving platform is a challenge but, once she has made that leap of faith, a rotary milking parlour can bring benefits to man and beast, according to herd manager Tim Lewis.

He joined the staff at a Frederick Hiam’s farm in Pembrokeshire in a year when the business switched from a 20/20 herringbone to a 40-point internal rotary parlour.

This enabled the farm to expand cow numbers from 280 to 440 without increasing labour.

Heifers brought into the herd to accelerate expansion settled almost immediately into the new system, but existing cattle took longer to adapt.

“It wasn’t the easiest thing to do because it was a totally different concept.

Cows had to be trained to walk onto something that was moving,” says Mr Lewis, who manages the Holstein Friesian herd at Lower Broadmoor Farm, Talbenny, Haverfordwest.

“By the third day heifers were coming in by themselves, but someone needed to be in the collecting yard for the first week to drive cows into the parlour.

It took them about three weeks to completely settle down.”

Mr Lewis reckons the system puts less stress on cows because they step one by one onto the platform instead of walking into the parlour in groups.

“Cows are content.

It is almost as if the platform movement puts them in a trance when they are being milked,” he says.

Cows walk in through an entry gate where auto-identification logs feed requirements.

A rapid-feed auger takes 1.3 seconds to transfer up to 3kg to a hopper and another 1.5 seconds to deposit it in the trough.

Each cow changeover takes 12 seconds and the platform rotates fully in 9.5 minutes.

Yields have climbed in recent years to an annual average of 8300 litres – mainly due to changes in management and feeding.

However, with only half the herd producing more than 26 litres/day, cows have to be split into two separate groups to optimise parlour efficiency.

Rotation speed is increased to manage the lower-yielding group.

“The most cows we can milk in an hour is 250, but at the end of the day we are governed by how quickly a cow steps onto the platform,” he says.

At peak, cows produce 4000 litres an hour – the most the system’s pumps can contend with.

When cows are in full production milking takes an average of three hours.

The system suits Mr Lewis, but he admits it wouldn’t appeal to everyone.

“I wouldn’t go back to working in a static parlour; with a rotary you can work in one place and see everything that’s going on,” he says.

“Some people might not like it because they like to take their time, but we are here to get cows through and milk them to a high standard.

We can still keep a close eye on how many litres they are producing.”

The herd has low cell counts – last year it won the National Milk Records competition for the lowest reading in Pembrokeshire with an average count of 84,000.

Mastitis runs at less than 1% in winter, but management and routines rather than the milking system are credited for this.

Maintenance is the biggest drawback of the rotary, reckons Mervyn Hopkins, farm manager at Lower Broadmoor Farm.

Because it is continually moving the drive units need regular maintenance.

Moving parts are greased every month and since the rotary at Lower Broadmoor Farm became operational it has only needed two new sets of drive wheels.

There has been one total breakdown during the six-and-a-half years since it was installed.

Although cows only missed one milking, it took them four weeks to recover because they were at the peak of their milk production.

A valve had jammed internally in the main hydraulic unit, explains Mr Hopkins.

He says a rotary suits the system at Lower Broadmoor Farm because they can milk more cows without increasing labour costs.

There is the option of increasing the herd size by another 60 cows – both the parlour and the farm infrastructure could cope with that expansion.