I don't blame you, I just looked and information is hard to locate regarding poultry in Oviedo. Here's what I came up with:
According to the BYC page, your lot must be zoned agricultural (A), but I'm not finding data to support that. Here is the zoning map for the city:
http://www.cityofoviedo.net/files/ZONING MAP -11-09-2011 3B.pdf
As you can see, not many "A" zones at all. And surprisingly, there is nothing in the city's municipal code regarding poultry or even livestock, the only thing under "ANIMALS" is about wild bird sanctuaries:
http://library.municode.com/HTML/14268/level3/PTIICOOR_CH10AN_ARTIINGE.html#TOPTITLE
In the city Zoning Ordinance there is a table showing the permitted uses for each zone, and there are two entries for "Agriculture":
"Agricultural Farming (excluding livestock)" is a permitted use of agriculture (A) and rural county estate (R-CE) zones.
"Agricultural Farming (including livestock, maximum 1 per acre)" is a special use (meaning you'd need a permit) for those zones too.
http://library.municode.com/HTML/14267/level1/ARTIVZODIRE.html#ARTIVZODIRE_S4.10PEUSSPEX
HOWEVER, this is how the zoning ordinance defines livestock:
"All animals of the equine, bovine, or swine class including, but not limited to goats, sheep, mules, horses, hogs, cattle and other grazing animals."
http://library.municode.com/HTML/14267/level1/ARTXVIIIBADEIN.html#TOPTITLE
Definitely doesn't sound like chickens! So all the being said, I don't see why you shouldn't be able to have chickens *anywhere* in the city. They aren't mentioned or prohibited anywhere in the municipal code or zoning ordinance. But if I were you, just to be safe, I would call the development office and be sure: 407-971-5775. Also check with them to see if your neighborhood has a subdivision covenant or HOA, but I think you would know about that since you'd have to either pay dues to the HOA or sign a covenant.
Good luck!!