After calving the cow needs to mobilise a lot of calcium. When this process is not functioning, the cow gets milk fever. Moreover, before and after calving the cow does not eat much and she loses a large amount of liquids and electrolytes. These need to be replenished, or the cow becomes weak and listless. By providing Farm-O-San Reviva once direct after calving, the cow revives quickly after the calving process and a positive start of lactation is given.