In "Our Casuarina Tree," What does the poet mean by the expression "sleepy cows"?

The speaker
is describing a morning scene as she wakes up and opens her casement (window) to look outside.
She sees a rural world, including her beloved casuarina tree. She mentions other items that come
into view, such as a baboon who has gotten up to greet the sun and the kokilas, which are birds.
Then she sees the sleepy cows heading toward the meadow to graze. She calls them sleepy because
it is early morning, and they have just woken up.

The speaker associates her
casuarina tree with rural India, where she grew up, and she tries to evoke the beauty and the
peaceful, natural aura of the scene with her descriptive details. Cows going off to graze are
part of that tableau. Because they are sleepy, we can imagine them perhaps moving slowly or
blinking their eyes as they wake up and take in the morning light.