CLUSTER MUST PASS MUSTER

4 February 2000

CLUSTER MUST PASS MUSTER

POOR cluster position is often overlooked in swing-over parlours that are commonly replacing one point/stall types to save money, but it is more critical in all parlours than producers realise.

ADAS milking technology specialist Ian Ohnstad says milking the udder evenly is essential to keep all teats in good condition and minimise mastitis risks. "Yet few producers see poor cluster position as a problem.

"Its important to distribute the weight evenly on each teat." In parlours with automatic cluster removal this means taking tension off ACR cords when every cluster is put on, he adds.

It is easier to achieve a good cluster position in a parlour with a cluster for each milking point. However, long milk tubes of the wrong length or poor cow position may make the cluster hang awkwardly.

"But more swing-over parlours are being put in, and in these its harder to get cluster position right."

Mr Ohnstad is convinced that a swing arm, supporting milk and pulse tubes, is essential to keep the cluster in the correct position. Also vital is an indexed rump rail ensuring the unit remains straight behind the cow.

"The nearer a cow is to 90 degrees of the swing-over arm, the easier it becomes to position the cluster correctly," he says. This should ensure cows milk out evenly and one-quarter – or more – is not left with more milk in it or other quarters overmilked.

Poor cluster position is a common cause of liner slip which also causes poor or uneven milking. But liner slip can be caused by many other factors, including lack of cluster support, the design and age of liners and vacuum level or reserve.

Teat cup liner replacement is often too infrequent, he adds. "Standard liners should be replaced every 2500 cow milkings and silicone ones every 6000 milking or 1500 hours of operation."

CLUSTERPOSITION

&#8226 It is important.

&#8226 Take tension off ACR cord.

&#8226 Check pipework length.

Its important to distribute cluster weight evenly on each teat, a more difficult task in swing-over parlours, according to Ian Ohnstad.