Udder wipes are important to farmers, even if most people don't realize the importance of cleaning the udders before milking cows. You clean and disinfect udders right before you pump the milk out, to make sure that the milk will not be contaminated. The contamination can often happen through your hands, ruining the milk in the process which is partly why hygiene is so important even when milking. Normally the milk coming out of the udder is completely sterile, so contamination generally happen after milking. It's the last chance for you to prevent microorganisms from fouling the milk. But while the udder wipes are made for cleaning cow udders, you can obviously use the wipes for other things as well, like around the house to clean surfaces and whatnot.
Outside of udder wipes there's disinfectants that are used as well to ensure that nothing gets into the milk as well as ensuring that infection does not happen. It's essential to make sure that udders do not get infected by keeping them clean and milking through proper methods so that the teats aren't infected as well. One of the common infections that can otherwise happen are mastitis and aren't always easily detected which makes it extremely important that you minimize the risks of infection with things like udder wipes. Outside of that, you still need cleaning milk production equipment and you use detergents to displace milk deposits, dissolve milk protein, emulsify the fat and aid the removal of dirt on the equipment.