Looking Fitz-Greene Halleck poem that begins:

Summer is over the old cow said 
and they'll lock me up in an empty shed

There is a book entitled:

Moo! Summer Is Over, the Old Cow Said.
By Robert Hillyer
Broadside, 1940.
6 x 4 inches.: 1940.

http://www.rosenet.org/library/GOLDENHIND%20PRESS.html (1/2 way down page)