Gopa

Gopa or Gop or Gope is a synonym of the Yadav (Ahir) caste.
Origin and History.
According to Bhagavata Purana, The Gopas (Ahirs) are re-incarnation of Devas. They are the messengers of Krishna, They are fond of Gavya or the products of Cows. The relation between Krishna and the Gopas (Ahirs) is that between an object and its image.
in the Rigveda, Vishnu is called Gopa (Ahir), a cowherd. His place is populated with 'many horned swiftly moving cows'. This is, in a way, the Goloka of Krishna described by the later Puranas.