Water content of milk is dependent upon the synthesis of lactose. Without some water in the milk, milk would be a viscous secretion composed mostly of lipid and protein and would be extremely difficult to remove from the gland. Upon birth, the mammalian neonate is not able to seek out its own water supply and would dehydrate rapidly without the water component of milk. Water content of milk can range from a low content in marine mammals (see below) to a high content in human milk and others. Cow milk is about 87% water, so the transport of milk from the dairy farm involves hauling considerable amounts of water.