1 August 1997

Robotics under review

The milking parlour is the hub of a dairy farm. Our special looks at maintenance, planning and building a replacement parlour, and heating during winter. We kick off this special with a look at the progress of the robotic milking machine at ADAS Bridgets. Jessica Buss reports

COWS are settling into the new robotic milking parlour at ADAS Bridgets, but experience so far suggests it will be a labour intensive operation for commercial herds.

So says farm manager, Robert Bull, who is now milking 40 cows through the Liberty Dairy Systems robotic milker installed three months ago at Martyr Worthy, Hants. This is the maximum capacity for a single stall unit milking three times a day, but that could be increased, as each robot could handle a further three stalls, he says.

"Cows have settled into the system well. Although it is still taking too much time and effort to get cows into the milking stall, this should improve over time." For two months, 20 cows were milked by the robot, and more recently a further two groups of 10 cows were added, each new group starting about seven days apart.

Cows come through the milking stall an average of 5.6 times a day, mostly at less than three-hour intervals. But cows are only milked three times a day, after a minimum gap of five hours. They must go through the stall to reach the feed barrier, and individual cows have varied, with some coming through the stall only twice a day.

Herdsman Mark Turney adds that training cows has taken about three weeks. "In the first week we pushed cows in, and for six milkings the cluster was put on manually to help cows get used to something different underneath them. After that the robot put the cluster on."

Once the first 20 cows were settled, the daily routine took two to three hours a day including feeding, bedding and washing through the milking machine twice a day, adds Mr Turney. He reckons it should take no longer to manage 40 cows once they are settled.

Although the robotic system relieves the monotony of milking, any time saved is taken up observing and monitoring cows.

Mr Turney, or a colleague, checks the milker every three or four hours during the day. Any cows not milked within eight to 10 hours are pushed into the stall.

He also carries a bleeper connected to the machine which has a two-tone alert, one for non-emergencies, such as no cows going through the stall, and one for emergencies. There has only been one emergency call so far, when the robot got stuck on its runners.

Mr Bull says initial problems with the robot locating the teats have been solved. But he is not convinced it will suit cows with a wider range of udder conformation and teat placement. Without some changes this could lead to a high culling rate, he believes.

Milk hygiene quality has been poor, with Bactoscans rising. Cows come in from the yard looking clean, so Mr Bull believes the clusters automatic washing system is at fault. This wets teats, but may not be washing away bacteria effectively. Now cows are dry stripped by the machine, which routinely discards milk for the first 15 seconds, says Mr Bull. Recent tests have shown an improvement in Bacto-scans, which are now in band A. There have been too many changes in cow management to accurately assess the yield effect of robotic milking, but it appears that yields and milk composition have not suffered. Yields average 34kg a day in 2.9 milkings. Cow cell counts are about 100,000/ml, equalling the main herd. "This is an indication that stress levels are low and cows are settled," says Mr Bull.

Mastitis levels are acceptable and incidence is similar to the main herd, he adds. In the first 20-cow group one cow had two cases of mastitis, and in the second 20 cows, two further mastitis cases were recorded, one of which was environmental.

Mastitis is detected by the robotic milker using in-line conductivity, which highlights cows with an 18% deviation on their own seven-day average. These cows are checked manually and treated. The computer orders the machine to dump the milk and rinse the cluster after mastitic cows. &#42

Milk yield and composition do not appear to have been affected by the change to robotic milking, says ADAS Bridgets farm manager, Robert Bull. But initially, Bactoscans rose and he believes the auto wash system was to blame.

Low cell counts and mastitis incidence suggests cow stress levels are low.

ROBOTIC MILKING

&#8226 Currently labour intensive.

&#8226 Cow stress levels low.

&#8226 Training cows takes time.