"Mother Yasoda would then address Nanda Maharaja, "See my dear son, whose eyes are white, who has a turban on His head, a wrapper on His body and leg bells which tinkle very sweetly on His feet. He is coming near, along with His surabhi calves, and just see how He is wandering upon the sacred land of Vrndavana!"
Nectar of Devotion, Chapter 43

"The cows in Krsna's abode are also liberated souls. They are called surabhi cows. There are many popular pictures showing how Krsna loves the cows, how He embraces and kisses them. That passive relationship with Krsna is called santa. Their perfect happiness is achieved when Krsna comes and simply touches them."

Science of Self-Realization, Chapter 8

"Krsna always tends the cows. His name is cowherd boy. To become animal of Krsna is a great, great fortune. It is not ordinary thing. Any associate of Krsna, either His cowherd boyfriends or calf or cows, or the Vrndavana trees, plants, flowers or water, they are all devotees of Krsna. They like to serve Krsna in different capacities. Somebody is serving Krsna as animal. Somebody is serving Krsna as fruits and flowers, as tree, as Yamuna water, or the beautiful cowherds men and damsels or Krsna's father and mother, so many with Krsna. Krsna is not imperson. So He has got so many lovers. Krsna also loves them. So Krsna's another name is pasu-pala, pasu-pala-pankaja. He is, mean, tender of the animals. Surabhir abhipalayantam. He takes pleasure in tending the cows, surabhi. These are surabhi cows, not these ordinary cows, surabhi cows. Surabhi cows means you can milk the cow as many times as you like and as much milk as you like. That is surabhi."

Srila Prabhupada Lecture on Srimad-Bhagavatam, 06-26-74, Melbourne

These cows are the Lord's pet animals. From the surabhi cows one can take as much milk as one needs, and one may milk these cows as many times as he desires. Of the surabhi cows, all of whom are very dear to Lord Krsna, seven are said to be the most important. They are: Mangala, Pingala, Ganga, Pisangi, Manikastani, Hamsi and Vamsipriya. Srimati Radharan also has pet surabhi cows, among whom Sunada, Yamuna and Bahula are the most important, along with Tungi, Her chubby pet calf.

In addition to these pet surabhi cows, many other types of pets belong to Krsna and Radharani. Krsna's pet dogs are Vyaghra and Bhramaraka. Padmagandha and Pisangaksa are His pet oxen, Suranga is His pet deer, and Dadhilobha is His monkey. Kalasvana is His pet swan, Tandavika His pet peacock, and Daksa and Vicaksana are His pet parrots.

Radharni's old pet monkey is called Kakkhati. Rangini is Her pet doe, Carucnadrika is Her pet cakori bird, and Madhuri is Her pet elephant. Tundikeri, Her pet swan, is fond of swimming in Radha-kunda. Suksmadhi and Subha, Her two parrots, like to perfectly imitate Lalita-devi's playful jokes spoken to her master and mistress (Sri Sri Radha-Krsna). By this wonderful repetition the parrots astonish the gopis.

"I think the drones that are buzzing all around You must have been Your devotees in their past lives. They cannot leave Your company because no one can be a better, more affectionate master than You. You are the supreme and original Personality of Godhead, and the drones are just trying to spread Your glories by chanting every moment. I think some of them must be great sages, devotees of Your Lordship, and they are disguising themselves in the form of drones because they are unable to give up Your company even for a moment. My dear brother, You are the supreme worshipable Godhead. Just see how the peacocks in great ecstasy are dancing before You. The deer, whose behavior is just like the gopis, are welcoming You with the same affection. And the cuckoos who are residing in this forest are receiving You with great joy, because they consider that Your appearance is so auspicious in their home. Even though they are trees and animals, these residents of Vrndavana are glorifying You. They are prepared to welcome You to their best capacity, as is the practice of great souls in receiving another great soul at home. As for the land, it is so pious and fortunate that the footprints of Your lotus feet are marking its body."

Krsna Book, Chapter 15
Bhaktivedanta Book Trust. HDG A.C. Bhaktivedanta Swami Srila Prabhupada.