A three-phased calf-rearing model has been developed by Atria: the dairy farm, calf-rearing facility and finishing facility all specialise in their own areas, so they are able to take care of animals in the best possible manner. Calves that are less than one month old are sensitive and require special care during their first few months in the calf-rearing facility. Calf-rearing requires producers to have strong attention to detail and ability to monitor the condition of animals. Calves are reared in groups. For the first few weeks, calves receive milk-based drinks, water and dry hay or pre-dried silage. As they get older, their diet expands to include mixed concentrated feed, and milk is entirely replaced by water when the calf is a couple of months old. Farms may have only calf-rearing facilities or combined calf-rearing and finishing facilities. From the calf-rearing units, the calves are sent for finishing at about 5 months of age.