 The milk is then stored in a large vat, or bulk tank, which is usually refrigerated until collection for processing.In countries where cows are grazed outside year-round, there is little waste disposal to deal with.The most concentrated waste is at the milking shed, where the animal waste may be liquefied (during the water-washing process) or left in a more solid form, either to be returned to be used on farm ground as organic fertilizer.