He described his session at DairyNZ’s Milksmart day at Clydevale in Otago in late March as “touchy feely”, handing around dozens of liners for farmers to compare.
A common complaint from farmers about their liners was slippage but cow comfort and the ability to milk out the quarters quickly were also important. He suggested changing two liners on the diagonal on several clusters to trial them during morning milking before buying.
“About 10 seconds after the cluster has been put on, pull down firmly but gently on the front shells supporting the claw in the other hand,” he said.
“A liner that is likely to slip will slide down the teat.”
Milking rate is easy to notice during milking but after milking farmers should also feel the quarters to see if the liners have milked the cow out cleanly. Lastly, he advised comparing the four teats once the cluster was removed.
“The more uncomfortable ones will distort teats and they may be swollen and discoloured particularly at the top of the teat,” he said.
“Turn the end of the teat upwards and it should be more or less round rather than wedge-shaped.”
Cows shifting their weight between their back legs, stamping their feet and even kicking the cups off were signs of discomfort during milking.
“Uncomfortable liners lead to poor milking out and eventually teat problems.”
He also suggested using different liners for the front quarters to the back.
“Back teats are usually shorter and thicker than front teats and back quarters usually contain one and half times the volume of milk compared with front quarters so you are asking the liners to do different jobs. I know on farms it’s often a management issue when changing liners but if you can work through that, you will milk out your cows better.”
Most importantly, liners always had to fit the shells and jetters correctly. The weight of clusters varied in NZ from 2kg to about 500g so liners also had to match these specifications.
“Remember, you don’t need weight to milk your cows, it’s about pulsation. Have clusters that are comfortable for you to hold and with which you can cup fast.
“Also modern cows often have smaller teats and may be unable to carry heavy clusters without slippage or discomfort. You may have to lower the cluster weight by either changing to a lighter claw or using lighter shells.”
He said NZ’s mainly synthetic rubber liners had a life of about 2500 milkings, depending on how well they were looked after.
“You need to have as a minimum two alkali washes per week, recycled for five to seven minutes, to ensure the removal of milk fat. Milk fat build-up will shorten the life of your liners. Also the mouthpiece of the liner will distort if left hanging on nipple jetters after washing.”
He said thicker walled liners lasted longer but liners with thinner walls seemed to perform better so were worth the cost of a slightly reduced life.
