A very strange mugshot of an ostrich led me to this. The text is not so much OZ as I'd thought, but does fit well into Animal Safari:

Fun with livestock, part I: How to deduct an ostrich:
The Society of Louisiana CPAs tax-hotline: "We took a call from an ostrich farmer in St. Tammany Parish who called in to find out how to go about depreciating an ostrich," he recalls. Strange as it sounds, you can depreciate an ostrich or any other livestock, as long as they're used for breeding.

Sex and the city
Then there was the client who approached Manhattan CPA _______ about a very personal tax matter. "He had made some money being a sperm donor and wanted to know if he could take a depletion allowance," Albaum recalls. "I told him he really needed to be an oil well or something like that."

Fun with livestock, part II
Which brings us to the tale of the crusty old Texas rancher who insisted upon accompanying his CPA, to the rancher's first tax audit. When the rancher's tax depreciation schedule listed 15 or 20 animals as breeding stock, the no-nonsense young IRS agent challenged the old cowboy. "I presume you breed these animals?" she asked pointedly. Without hesitation, the rancher replied, "Nope," sending his CPA into mild tachycardia. After a sufficient pause, the rancher finished, "I've got a bull for that."