Actually, I've just checked Sophocles' Ajax, and it was a combination of sheep and cows. I'll put a transliteration of the Greek here:
"...tous zontas au desmoisi sundesas boon poimnas te pasas eis domous komizetai..."
"...having bound together all the living animals from the oxen and the flock [of sheep] he took them home..."
Soph. Ajax 62-3 (my own translation, admittedly not perfectly idiomatic)
So there you have it. Also see the Cena Trimalchionis in the Satyricon of Titus Petronius Niger, in which the actor portraying Ajax in this scene slays an ox.
Not that this has any particular bearing on the mod.