From the November 29, 1910 Brooklyn Daily Eagle:

“Washington–‘Big Bill,’ the son of ‘Mrs. Wayne,’ the White House cow, is dead. Brain fever caused the blue-blooded young bovine’s demise. ‘Big Bill’ had been promised by President Taft to ‘Big Bill’ Price, the dean of the White House correspondents, and was soon to have been transferred to a Maryland farm, where a special stable had been made ready for his reception.”