सर्वोपनिषदो गावो दोग्धा गोपालनन्दनः ।
पार्थो वत्सः सुधीर्भोक्ता दुग्धं गीतामृतं महत् ॥

All the UpaniShads are the cows, the son of the cowherd (Krishna) is the milker, Partha (Arjuna) is teh calf, men of purified intellect are the drinkers and the supreme nectar Gita is the milk.

Word meanings:
सर्वोपनिषदो = all the `upanishad’s or Vedanta;
गावो = cows;
दोग्धा = the milking man;
गोपालनन्दनः = the delightful protector of cows; refers to Krishna;
पार्थो = Partha; Arjuna;
वत्सः = child; the young one;
सुधीर्भोक्ता = the intellect is the eater or enjoyer;
दुग्धं = milk;
गीतामृतं = nectar-like gita;
महत् = great; big;