You can purchase inexpensive devices designed specifically for navel dipping. They're well worth it. According to Dr. G.A. Donovan, University of Florida, you should dip the navel as soon as possible after birth, when you move the calf to the hutch or pen, and again 12 to 18 hours later. Remember, dipping the navel is one way to reduce an animal's exposure to disease causing pathogens. It's easy, inexpensive, and pays great dividends in terms of reduced calf mortality, morbidity, and treatment expenses.
Short hair is easier to keep clean and dry.
Long hair is difficult to clean and dry, and wet teats are often milked. Many herds are finding it easier and faster to burn the hair on the udder rather than clip. Using a propane torch to singe the hair off is quick and painless. When done correctly, burning the teats and udder doesn't occur. We have done it three years in our herd.