Srila Prabhupada

The cows, oh, as soon as they see Kṛṣṇa, they become . . . they lick up His feet and body, and every cow has got a different name. As soon as He will call, the cow will come immediately, and dropping milk. And those cows are also spiritual. Surabhī. It is described in the Brahma-saṁhitā, surabhīr abhipālayantam (Bs 5.29).
Surabhī. Surabhī cow means nonexhaustive. You can milk as much milk you want and as many times. In the material world the cow is limited. There is time that you can milk, morning and evening, and so much quantity, not more than that. But surabhīr means you can milk those cows anytime you like, and you can draw milk as many as you like, as much as you like. This is called surabhī. urabhīr . . . in the description of Brahma-saṁhitā: cintāmaṇi-prakara-sadmasu kalpa-vṛkṣa-lakṣāvṛteṣu surabhīr abhipālayantam. Surabhīr abhipālayantam. So therefore He is Govinda. He gives . . . He is pleasure for everyone.
(661211 - Lecture CC Madhya 20.152-154 - New York)