Liners are a combination of art and science. More science is needed. For example, there are about 300 different designs available in the United States. Fewer than half of them really perform well. Very few know that there is an interaction of liner and vacuum. In other words, some liners have characteristics to be used at a higher vacuum than other liners which have a low resistance to collapse and are thus a low vacuum liner. Electronic meters give an opportunity to evaluate liners with respect to machine on time, peak flow, average flow, and yield. Few trials have been done to optimize liners to their vacuum and ratio. Tests such as these need to be subjected to statistical evaluation because the differences are sometimes quite small. Sometimes there are wide differences among liners but not realized because just casual observation is inadequate to tell the difference. This may sound impractical, but it is not. Cows deserve the best liners available and improvements in performance are feasible.
Stephen Spencer, Professor Emeritus, Pennsylvania State University
There probably is not one liner for everybody. If the liner you now use milks the cows as you like with fast gentle milk outs and few liner slips and/or fall-offs, the majority of the teat ends look good, and this performance lasts throughout the stated life of the liner, keep it. If you are looking for long life, you have silicone liners. There are triangle, squares, and you can get almost all with vents in them, which allows for faster milk evacuation in fast milking cows, but can increase fall-offs in herds milking at low vacuum. Vacuum level, claw weight, and dryness of teats and udders all contribute to performance. There are no real data to suggest that one liner is better than another.
David Bray, Extension Dairy Specialist, University of Florida
