15 September 2000

ROBOTICTOPICS INMIND

With interest in robotic

milking steadily gathering

momentum this years EDFE

provides an ideal forum to

check out the latest

developments. Over the next

few pages we take a

look at whats hot in robotic

milking, starting with an

update on Dutch research,

Marianne Curtis reports

IT MAY take dairy producers longer to get the hang of working with milking robots than their cows, according to Albert Meijering, research head at the Research Institute for Animal Husbandry in Lelystad, Holland.

"Producers no longer see their cows twice a day in the milking parlour so detecting health problems is more difficult," he says.

"They must learn to manage the herd based on data such as milk conductivity, time period between milkings and feed consumption."

However, conductivity measurements, which can give early warnings of mastitis infection, should be used with caution, he adds. "They do throw up occasional false negatives and false positives. We need to work on other methods such as being able to detect clots in milk, the definitive symptom of clinical mastitis."

But whatever answers technology may come up with, there is no substitute for good stockmanship, says Henk Hogeveen, also a researcher at the institute. "Time must be spent observing cows for signs of ill health. You can have the best sensors in the world but if theyre not used properly theyre useless. When a cow has gone for longer than 14 hours without being milked, look out for a problem."

Research at the institute and elsewhere is focusing on how milking robots can be incorporated into different farming systems. A detailed three-year EU project involving nine countries will commence shortly. Subjects will include how robotic milking affects health and welfare, milk quality, grazing systems and economics.

Earlier research concentrated on how cow traffic through the milking robot is best controlled, says Dr Meijering.

"There are two methods of controlling cow traffic. The first involves separating cow lying and feeding areas by the robot which means cows have to go through it before they can feed. This system works well when first teaching cows to use the robot, however, it can lead to aggression between high and low ranking cows.

"A better system is where cows have free access to lying and feeding areas without having to pass through the robot. This is better for cow welfare and temperament." Cows receive concentrates in the robot in both systems to tempt them in.

Operating a milking robot in conjunction with a grazing system poses a different set of challenges, says Dr Meijering. "Pasture must be available close to the holding, otherwise cow walking distances are long and yield may suffer because cows are walking rather than grazing."

But in general, milk yield should increase compared with conventional milking because cows are being milked more frequently, says Dr Hogeveen. "While yield can increase by 10-15%, a 5-10% increase is likely to be achieved in a practical farm situation.

"However, producers already milking three times a day rather than twice may possibly see a yield decrease as cows may not come to the robot three times a day."

Although yield will generally increase, the amount of milk flowing through the system at any one time will be dramatically less than in a conventional milking system, says Dr Hogeveen. "Milk cooling requires a different approach from conventional milking and needs careful consideration before purchase.

"Milk will be flowing relatively slowly in a robotic system and could freeze. Also the slower flow of milk may allow more opportunity for bacteria to grow which can lead to problems with Bactoscans. The whole system should be programmed to fully clean itself every eight hours."

All this cleaning, in addition to cleaning cows udders at each milking means water and energy consumption on the unit will increase dramatically, he says. "Each time the cluster is cleaned when a cow is milked, 1.5 litres of water is used."

The continuous nature of the process can also present difficulties for milk collection. "A buffer tank is needed so that there is no disruption to robotic milking while cooled milk is being collected from the bulk tank," adds Dr Hogeveen.

So with all these challenges to overcome, why would anyone choose a milking robot? "Labour is a costly resource: Assuming that an 80-cow herd requires 4000-4500 working hours a year, a milking robot has the potential to save 850 of these. It also allows staff more freedom to do other tasks."

MILESTONES

1980s Development of robot technology.

1990s Research on cow flow through robot.

2000s Research on how robots fit different farming systems.

Getting cow traffic to the robot right is critical to avoid jams. Operating a robotic milking system requires an entirely different approach to herd management, says Albert Meijering.