In rotary parlors, the cows are loaded one at a time onto the parlor as the whole thing rotates in a circle. One milker stands near the entry to the parlor and pre-dips the teats on the udder to help prevent bacteria from entering. The next milker puts the machine on the cow to begin milking. By the time the platform has completed almost a full rotation, the cow is done milking and the unit will come off automatically. The last milker will post-dip her teats to protect them before entering back into the pen. Once this process is done, the cow will back out of the parlor and return to the barn. Rotary cowsheds, as they are called in New Zealand, started in the 1980s but are expensive compared to Herringbone cowshed – the older New Zealand norm.