What imagery is used in "Beasts of England"?

In the novella Animal Farm, Old Major—one of the senior pigs and "father" of the revolution—dreams of a world that is dominated by animals. This dream inspires the lyrics of "Beasts of England."
The song became a form of revolutionary manifesto for the animals on the farm. George Orwell based "Beasts of England" on "The Internationale" and "Men of England." The tune is prophetic in nature and thus uses vivid imagery.
Like many nationalistic melodies and odes, "Beasts of England" glorifies the beauty of the nation's landscape. The song contains descriptions of fields and other natural surroundings, such as:

And the fruitful fields of EnglandShall be trod by beasts alone.

The lyrics also contain hints of utopian visions, which is typical of nationalist songs and revolutionary odes. For instance, the song contains the following lines:

Bright will shine the fields of England,Purer shall its waters be . . .

The second line illustrates the tone of the animals' vision of the future: that they will inherit the Earth and return it to its past purity. In contrast, the humans, in the animals' perspective, are dirty polluters of the land.