All glories to Krishna, the son of Mother Yasoda, the cowherd boy Gopal, Govinda who gives pleasure to the cows! All glories to the conqueror of Cupid, Lord Hari, who takes away all inauspiciousness, who is unlimited, and the awarder of liberation! (Gitavali)
I worship Govinda, the primeval Lord, the first progenitor who is tending the cows, yielding all desire, in abodes built with spiritual gems, surrounded by millions of purpose trees, always served with great reverence and affection by hundreds of thousands of lakshmis or gopis. (Sri Brahma-samhita 5.29)
May that Lord of the cows be satisfied by us. Who is Indra when compared to Krishna? Krishna is the master of Indra. And yet He has appeared as the master of cows; the Supreme Absolute Truth has accepted a simple position as the keeper of cows. (Srimad-Bhagavatam )
Superficially, He is a mere cowherd boy. But let that cowherd boy, who holds within Him the power of controlling the whole universe, be satisfied with us. We want to worship that Lord who has taken the humble position of the king of the cows.
Abandoning their calves, the young cows joyfully worship Krishna with abundant nectarean milk. With great love Krishna always protects them. In this way Lord Krishna, who always protects everyone, became eternally famous as Gopal, protector of the cows. (Sri-hari-bhakti-kalpa-latika)